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David Hildenbrand
df25569d40 mm: rename PAGE_MAPPING_* to FOLIO_MAPPING_* 
Now that the mapping flags are only used for folios, let's rename the
defines.

Link: https://lkml.kernel.org/r/20250704102524.326966-27-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Eugenio Pé rez <eperezma@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-07-13 16:38:31 -07:00
Alistair Popple
fd2825b076 mm/gup: remove pXX_devmap usage from get_user_pages() 
GUP uses pXX_devmap() calls to see if it needs to a get a reference on the
associated pgmap data structure to ensure the pages won't go away. 
However it's a driver responsibility to ensure that if pages are mapped
(ie.  discoverable by GUP) that they are not offlined or removed from the
memmap so there is no need to hold a reference on the pgmap data structure
to ensure this.

Furthermore mappings with PFN_DEV are no longer created, hence this
effectively dead code anyway so can be removed.

Link: https://lkml.kernel.org/r/708b2be76876659ec5261fe5d059b07268b98b36.1750323463.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Björn Töpel <bjorn@rivosinc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Inki Dae <m.szyprowski@samsung.com>
Cc: John Groves <john@groves.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-07-09 22:42:16 -07:00
Lorenzo Stoakes
bfbe71109f mm: update core kernel code to use vm_flags_t consistently 
The core kernel code is currently very inconsistent in its use of
vm_flags_t vs.  unsigned long.  This prevents us from changing the type of
vm_flags_t in the future and is simply not correct, so correct this.

While this results in rather a lot of churn, it is a critical
pre-requisite for a future planned change to VMA flag type.

Additionally, update VMA userland tests to account for the changes.

To make review easier and to break things into smaller parts, driver and
architecture-specific changes is left for a subsequent commit.

The code has been adjusted to cascade the changes across all calling code
as far as is needed.

We will adjust architecture-specific and driver code in a subsequent patch.

Overall, this patch does not introduce any functional change.

Link: https://lkml.kernel.org/r/d1588e7bb96d1ea3fe7b9df2c699d5b4592d901d.1750274467.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Kees Cook <kees@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-07-09 22:42:13 -07:00
Li Zhe
a03db236ae gup: optimize longterm pin_user_pages() for large folio 
In the current implementation of longterm pin_user_pages(), we invoke
collect_longterm_unpinnable_folios().  This function iterates through the
list to check whether each folio belongs to the "longterm_unpinnabled"
category.  The folios in this list essentially correspond to a contiguous
region of userspace addresses, with each folio representing a physical
address in increments of PAGESIZE.

If this userspace address range is mapped with large folio, we can
optimize the performance of function collect_longterm_unpinnable_folios()
by reducing the using of READ_ONCE() invoked in
pofs_get_folio()->page_folio()->_compound_head().

Also, we can simplify the logic of collect_longterm_unpinnable_folios(). 
Instead of comparing with prev_folio after calling pofs_get_folio(), we
can check whether the next page is within the same folio.

The performance test results, based on v6.15, obtained through the
gup_test tool from the kernel source tree are as follows.  We achieve an
improvement of over 66% for large folio with pagesize=2M.  For small
folio, we have only observed a very slight degradation in performance.

Without this patch:

    [root@localhost ~] ./gup_test -HL -m 8192 -n 512
    TAP version 13
    1..1
    # PIN_LONGTERM_BENCHMARK: Time: get:14391 put:10858 us#
    ok 1 ioctl status 0
    # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
    [root@localhost ~]# ./gup_test -LT -m 8192 -n 512
    TAP version 13
    1..1
    # PIN_LONGTERM_BENCHMARK: Time: get:130538 put:31676 us#
    ok 1 ioctl status 0
    # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0

With this patch:

    [root@localhost ~] ./gup_test -HL -m 8192 -n 512
    TAP version 13
    1..1
    # PIN_LONGTERM_BENCHMARK: Time: get:4867 put:10516 us#
    ok 1 ioctl status 0
    # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
    [root@localhost ~]# ./gup_test -LT -m 8192 -n 512
    TAP version 13
    1..1
    # PIN_LONGTERM_BENCHMARK: Time: get:131798 put:31328 us#
    ok 1 ioctl status 0
    # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0

[lizhe.67@bytedance.com: whitespace fix, per David]
  Link: https://lkml.kernel.org/r/20250606091917.91384-1-lizhe.67@bytedance.com
Link: https://lkml.kernel.org/r/20250606023742.58344-1-lizhe.67@bytedance.com
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-07-09 22:42:06 -07:00
David Hildenbrand
792b429db7 mm/gup: remove (VM_)BUG_ONs 
Especially once we hit one of the assertions in
sanity_check_pinned_pages(), observing follow-up assertions failing in
other code can give good clues about what went wrong, so use
VM_WARN_ON_ONCE instead.

While at it, let's just convert all VM_BUG_ON to VM_WARN_ON_ONCE as well. 
Add one comment for the pfn_valid() check.

We have to introduce VM_WARN_ON_ONCE_VMA() to make that fly.

Drop the BUG_ON after mmap_read_lock_killable(), if that ever returns
something > 0 we're in bigger trouble.  Convert the other BUG_ON's into
VM_WARN_ON_ONCE as well, they are in a similar domain "should never
happen", but more reasonable to check for during early testing.

[david@redhat.com: use the _FOLIO variant where possible, per Lorenzo]
  Link: https://lkml.kernel.org/r/844bd929-a551-48e3-a12e-285cd65ba580@redhat.com
Link: https://lkml.kernel.org/r/20250604140544.688711-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-07-09 22:41:56 -07:00
David Hildenbrand
517f496e1e mm/gup: revert "mm: gup: fix infinite loop within __get_longterm_locked" 
After commit 1aaf8c1229 ("mm: gup: fix infinite loop within
__get_longterm_locked") we are able to longterm pin folios that are not
supposed to get longterm pinned, simply because they temporarily have the
LRU flag cleared (esp.  temporarily isolated).

For example, two __get_longterm_locked() callers can race, or
__get_longterm_locked() can race with anything else that temporarily
isolates folios.

The introducing commit mentions the use case of a driver that uses
vm_ops->fault to insert pages allocated through cma_alloc() into the page
tables, assuming they can later get longterm pinned.  These pages/ folios
would never have the LRU flag set and consequently cannot get isolated. 
There is no known in-tree user making use of that so far, fortunately.

To handle that in the future -- and avoid retrying forever to
isolate/migrate them -- we will need a different mechanism for the CMA
area *owner* to indicate that it actually already allocated the page and
is fine with longterm pinning it.  The LRU flag is not suitable for that.

Probably we can lookup the relevant CMA area and query the bitmap; we only
have have to care about some races, probably.  If already allocated, we
could just allow longterm pinning)

Anyhow, let's fix the "must not be longterm pinned" problem first by
reverting the original commit.

Link: https://lkml.kernel.org/r/20250611131314.594529-1-david@redhat.com
Fixes: 1aaf8c1229 ("mm: gup: fix infinite loop within __get_longterm_locked")
Signed-off-by: David Hildenbrand <david@redhat.com>
Closes: https://lore.kernel.org/all/20250522092755.GA3277597@tiffany/
Reported-by: Hyesoo Yu <hyesoo.yu@samsung.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Peter Xu <peterx@redhat.com>
Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Cc: Aijun Sun <aijun.sun@unisoc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-06-19 20:48:01 -07:00
Jann Horn
52084f258e mm/gup: update comment explaining why gup_fast() disables IRQs 
The current comment in gup_fast() talks about "IPIs that come from THPs
splitting", which is outdated and refers to the old THP splitting
implementation that was removed in commit ad0bed24e9 ("thp: drop all
split_huge_page()-related code"), which landed in v4.5.  Before then, THP
splitting involved a pmdp_splitting_flush(), which sent an IPI to
serialize against gup_fast().

Nowadays, we use tlb_remove_table_sync_one() to send IPIs that serialize
against gup_fast(); this is used, for example, in THP *collapsing* to stop
gup_fast() walks of a page table before depositing it.

Link: https://lkml.kernel.org/r/20250528-gup-irq-comment-fix-v1-1-b9d83c345333@google.com
Signed-off-by: Jann Horn <jannh@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-31 22:46:14 -07:00
Feng Lee
0cad6736f4 mm: remove obsolete pgd_offset_gate() 
Remove pgd_offset_gate() completely and simply make the single caller use
pgd_offset().

It appears that the gate area resides in the kernel-mapped segment
exclusively on IA64.  Therefore, removing pgd_offset_k is safe since IA64
is now obsolete.

Link: https://lkml.kernel.org/r/tencent_503130C3CD56569191396268CF4D12F09A06@qq.com
Signed-off-by: Feng Lee <379943137@qq.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: bibo mao <maobibo@loongson.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-13 16:28:08 -07:00
Vishal Moola (Oracle)
fe488d34ed mm/gup: remove page_folio() in memfd_pin_folios() 
We can get the folio directly from the folio batch, so remove the
unnecessary page_folio() call.

Link: https://lkml.kernel.org/r/20250430010059.892632-3-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-12 23:50:51 -07:00
Vishal Moola (Oracle)
30f62b92e6 mm/gup: remove unnecessary check in memfd_pin_folios() 
Patch series "mm/gup: Cleanup memfd_pin_folios()".

A couple straightforward cleanups to memfd_pin_folios() found through code
inspection.  Saves 124 bytes of kernel text overall and makes the code
more readable.


This patch (of 2):

Commit 89c1905d9c ("mm/gup: introduce memfd_pin_folios() for pinning
memfd folios") checks if filemap_get_folios_contig() returned duplicate
folios to prevent multiple attempts at pinning the same folio.

Commit 8ab1b16023 ("mm: fix filemap_get_folios_contig returning batches
of identical folios") ensures that filemap_get_folios_contig() returns a
batch of distinct folios.

We can remove the duplicate folio check to simplify the code and save 58
bytes of text.

Link: https://lkml.kernel.org/r/20250430010059.892632-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20250430010059.892632-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-12 23:50:51 -07:00
Kairui Song
7d0f0f0615 mm: move folio_index to mm/swap.h and remove no longer needed helper 
There are no remaining users of folio_index() outside the mm subsystem. 
Move it to mm/swap.h to co-locate it with swap_cache_index(), eliminating
a forward declaration, and a function call overhead.

Also remove the helper that was used to fix circular header dependency
issue.

Link: https://lkml.kernel.org/r/20250430181052.55698-6-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Joanne Koong <joannelkoong@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Qu Wenruo <wqu@suse.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-12 23:50:50 -07:00
Baoquan He
a7797e74bd mm/gup: clean up codes in fault_in_xxx() functions 
The code style in fault_in_readable() and fault_in_writable() is a little
inconsistent with fault_in_safe_writeable().  In fault_in_readable() and
fault_in_writable(), it uses 'uaddr' passed in as loop cursor.  While in
fault_in_safe_writeable(), local variable 'start' is used as loop cursor. 
This may mislead people when reading code or making change in these codes.

Here define explicit loop cursor and use for loop to simplify codes in
these three functions.  These cleanup can make them be consistent in code
style and improve readability.

[bhe@redhat.com: address minor concerns from David]
  Link: https://lkml.kernel.org/r/Z/sbv3EmLXWgEE7+@MiWiFi-R3L-srv
Link: https://lkml.kernel.org/r/20250410035717.473207-5-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yanjun.Zhu <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-11 17:48:31 -07:00
Baoquan He
339122abb5 mm/gup: remove gup_fast_pgd_leaf() and clean up the relevant codes 
In the current kernel, only pud huge page is supported in some
architectures.  P4d and pgd huge pages haven't been supported yet.  And in
mm/gup.c, there's no pgd huge page handling in the follow_page_mask() code
path.  Hence it doesn't make sense to only have gup_fast_pgd_leaf() in
gup_fast code path.

Here remove gup_fast_pgd_leaf() and clean up the relevant codes.

Link: https://lkml.kernel.org/r/20250410035717.473207-4-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Yanjun.Zhu <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-11 17:48:31 -07:00
Baoquan He
ede27b7ee2 mm/gup: remove unneeded checking in follow_page_pte() 
Patch series "mm/gup: Minor fix, cleanup and improvements", v4.

These were made from code inspection in mm/gup.c.


This patch (of 3):

In __get_user_pages(), it will traverse page table and take a reference to
the page the given user address corresponds to if GUP_GET or GUP_PIN is
set.  However, it's not supported both GUP_GET and GUP_PIN are set.  Even
though this check need be done, it should be done earlier, but not doing
it till entering into follow_page_pte() and failed.

Furthermore, this checking has been done in is_valid_gup_args() and all
external users of __get_user_pages() will call is_valid_gup_args() to
catch the illegal setting.  We don't need to worry about internal users of
__get_user_pages() because the gup_flags are set by MM code correctly.

Here remove the checking in follow_page_pte(), and add VM_WARN_ON_ONCE()
to catch the possible exceptional setting just in case.

And also change the VM_BUG_ON to VM_WARN_ON_ONCE() for checking (!!pages
!= !!(gup_flags & (FOLL_GET | FOLL_PIN))) because the checking has been
done in is_valid_gup_args() for external users of __get_user_pages().

Link: https://lkml.kernel.org/r/20250410035717.473207-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20250410035717.473207-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Yanjun.Zhu <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-05-11 17:48:31 -07:00
Baoquan He
8c03ebd7cd mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable() 
Not like fault_in_readable() or fault_in_writeable(), in
fault_in_safe_writeable() local variable 'start' is increased page by page
to loop till the whole address range is handled.  However, it mistakenly
calculates the size of the handled range with 'uaddr - start'.

Fix it here.

Andreas said:

: In gfs2, fault_in_iov_iter_writeable() is used in
: gfs2_file_direct_read() and gfs2_file_read_iter(), so this potentially
: affects buffered as well as direct reads.  This bug could cause those
: gfs2 functions to spin in a loop.

Link: https://lkml.kernel.org/r/20250410035717.473207-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20250410035717.473207-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Fixes: fe673d3f5b ("mm: gup: make fault_in_safe_writeable() use fixup_user_fault()")
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Yanjun.Zhu <yanjun.zhu@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-04-17 20:10:07 -07:00
Linus Torvalds
eb0ece1602 - The 6 patch series "Enable strict percpu address space checks" from 
Uros Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.
 
   This has caused a small amount of fallout - two or three issues were
   reported.  In all cases the calling code was founf to be incorrect.
 
 - The 4 patch series "Some cleanup for memcg" from Chen Ridong
   implements some relatively monir cleanups for the memcontrol code.
 
 - The 17 patch series "mm: fixes for device-exclusive entries (hmm)"
   from David Hildenbrand fixes a boatload of issues which David found then
   using device-exclusive PTE entries when THP is enabled.  More work is
   needed, but this makes thins better - our own HMM selftests now succeed.
 
 - The 2 patch series "mm: zswap: remove z3fold and zbud" from Yosry
   Ahmed remove the z3fold and zbud implementations.  They have been
   deprecated for half a year and nobody has complained.
 
 - The 5 patch series "mm: further simplify VMA merge operation" from
   Lorenzo Stoakes implements numerous simplifications in this area.  No
   runtime effects are anticipated.
 
 - The 4 patch series "mm/madvise: remove redundant mmap_lock operations
   from process_madvise()" from SeongJae Park rationalizes the locking in
   the madvise() implementation.  Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.
 
 - The 12 patch series "Tiny cleanup and improvements about SWAP code"
   from Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.
 
 - The 2 patch series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak user-visible
   output.
 
 - The 2 patch series "mm/damon/paddr: fix large folios access and
   schemes handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.
 
 - The 3 patch series "mm/damon/core: fix wrong and/or useless
   damos_walk() behaviors" from SeongJae Park fixes a few issues with the
   accuracy of kdamond's walking of DAMON regions.
 
 - The 3 patch series "expose mapping wrprotect, fix fb_defio use" from
   Lorenzo Stoakes changes the interaction between framebuffer deferred-io
   and core MM.  No functional changes are anticipated - this is
   preparatory work for the future removal of page structure fields.
 
 - The 4 patch series "mm/damon: add support for hugepage_size DAMOS
   filter" from Usama Arif adds a DAMOS filter which permits the filtering
   by huge page sizes.
 
 - The 4 patch series "mm: permit guard regions for file-backed/shmem
   mappings" from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state.  The feature now covers shmem and
   file-backed mappings.
 
 - The 4 patch series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping for
   pte-mapped large folios.
 
 - The 18 patch series "reimplement per-vma lock as a refcount" from
   Suren Baghdasaryan puts the vm_lock back into the vma.  Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy.  This patchset provides small (0-10%) improvements on one
   microbenchmark.
 
 - The 5 patch series "Docs/mm/damon: misc DAMOS filters documentation
   fixes and improves" from SeongJae Park does some maintenance work on the
   DAMON docs.
 
 - The 27 patch series "hugetlb/CMA improvements for large systems" from
   Frank van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for unmapped
   pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.
 
 - The 19 patch series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.
 
 - The 12 patch series "selftests/mm: Some cleanups from trying to run
   them" from Brendan Jackman fixes a pile of unrelated issues which
   Brendan encountered while runnimg our selftests.
 
 - The 2 patch series "fs/proc/task_mmu: add guard region bit to pagemap"
   from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.
 
 - The 7 patch series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply wasn't
   being effective.
 
 - The 5 patch series "mm: cleanups for device-exclusive entries (hmm)"
   from David Hildenbrand implements a number of unrelated cleanups in this
   code.
 
 - The 5 patch series "mm: Rework generic PTDUMP configs" from Anshuman
   Khandual implements a number of preparatoty cleanups to the
   GENERIC_PTDUMP Kconfig logic.
 
 - The 8 patch series "mm/damon: auto-tune aggregation interval" from
   SeongJae Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.
 
 - The 5 patch series "Fix lazy mmu mode" from Ryan Roberts fixes some
   issues in powerpc, sparc and x86 lazy MMU implementations.  Ryan did
   this in preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.
 
 - The 2 patch series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the code
   easier to follow.
 
 - The 3 patch series "page_counter cleanup and size reduction" from
   Shakeel Butt cleans up the page_counter code and fixes a size increase
   which we accidentally added late last year.
 
 - The 3 patch series "Add a command line option that enables control of
   how many threads should be used to allocate huge pages" from Thomas
   Prescher does that.  It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.
 
 - The 3 patch series "Fix calculations in trace_balance_dirty_pages()
   for cgwb" from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.
 
 - The 9 patch series "mm/damon: make allow filters after reject filters
   useful and intuitive" from SeongJae Park improves the handling of allow
   and reject filters.  Behaviour is made more consistent and the
   documention is updated accordingly.
 
 - The 5 patch series "Switch zswap to object read/write APIs" from Yosry
   Ahmed updates zswap to the new object read/write APIs and thus permits
   the removal of some legacy code from zpool and zsmalloc.
 
 - The 6 patch series "Some trivial cleanups for shmem" from Baolin Wang
   does as it claims.
 
 - The 20 patch series "fs/dax: Fix ZONE_DEVICE page reference counts"
   from Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.
 
 - The 4 patch series "refactor mremap and fix bug" from Lorenzo Stoakes
   is a preparatoty refactoring and cleanup of the mremap() code.
 
 - The 20 patch series "mm: MM owner tracking for large folios (!hugetlb)
   + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.
 
 - The 8 patch series "mm/damon: add sysfs dirs for managing DAMOS
   filters based on handling layers" from SeongJae Park adds a couple of
   new sysfs directories to ease the management of DAMON/DAMOS filters.
 
 - The 13 patch series "arch, mm: reduce code duplication in mem_init()"
   from Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.
 
 - The 13 patch series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.
 
 - The 3 patch series "mm: page_ext: Introduce new iteration API" from
   Luiz Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.
 
 - The 8 patch series "Buddy allocator like (or non-uniform) folio split"
   from Zi Yan reworks the code to split a folio into smaller folios.  The
   main benefit is lessened memory consumption: fewer post-split folios are
   generated.
 
 - The 2 patch series "Minimize xa_node allocation during xarry split"
   from Zi Yan reduces the number of xarray xa_nodes which are generated
   during an xarray split.
 
 - The 2 patch series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.
 
 - The 3 patch series "Add tracepoints for lowmem reserves, watermarks
   and totalreserve_pages" from Martin Liu adds some more tracepoints to
   the page allocator code.
 
 - The 4 patch series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which SeongJae
   observed during his earlier madvise work.
 
 - The 3 patch series "mm/hwpoison: Fix regressions in memory failure
   handling" from Shuai Xue addresses two quite serious regressions which
   Shuai has observed in the memory-failure implementation.
 
 - The 5 patch series "mm: reliable huge page allocator" from Johannes
   Weiner makes huge page allocations cheaper and more reliable by reducing
   fragmentation.
 
 - The 5 patch series "Minor memcg cleanups & prep for memdescs" from
   Matthew Wilcox is preparatory work for the future implementation of
   memdescs.
 
 - The 4 patch series "track memory used by balloon drivers" from Nico
   Pache introduces a way to track memory used by our various balloon
   drivers.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for active
   pages" from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.
 
 - The 2 patch series "Adding Proactive Memory Reclaim Statistics" from
   Hao Jia separates the proactive reclaim statistics from the direct
   reclaim statistics.
 
 - The 2 patch series "mm/vmscan: don't try to reclaim hwpoison folio"
   from Jinjiang Tu fixes our handling of hwpoisoned pages within the
   reclaim code.
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Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "Enable strict percpu address space checks" from Uros
   Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.

   This has caused a small amount of fallout - two or three issues were
   reported. In all cases the calling code was found to be incorrect.

 - The series "Some cleanup for memcg" from Chen Ridong implements some
   relatively monir cleanups for the memcontrol code.

 - The series "mm: fixes for device-exclusive entries (hmm)" from David
   Hildenbrand fixes a boatload of issues which David found then using
   device-exclusive PTE entries when THP is enabled. More work is
   needed, but this makes thins better - our own HMM selftests now
   succeed.

 - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
   remove the z3fold and zbud implementations. They have been deprecated
   for half a year and nobody has complained.

 - The series "mm: further simplify VMA merge operation" from Lorenzo
   Stoakes implements numerous simplifications in this area. No runtime
   effects are anticipated.

 - The series "mm/madvise: remove redundant mmap_lock operations from
   process_madvise()" from SeongJae Park rationalizes the locking in the
   madvise() implementation. Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.

 - The series "Tiny cleanup and improvements about SWAP code" from
   Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.

 - The series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak
   user-visible output.

 - The series "mm/damon/paddr: fix large folios access and schemes
   handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.

 - The series "mm/damon/core: fix wrong and/or useless damos_walk()
   behaviors" from SeongJae Park fixes a few issues with the accuracy of
   kdamond's walking of DAMON regions.

 - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
   Stoakes changes the interaction between framebuffer deferred-io and
   core MM. No functional changes are anticipated - this is preparatory
   work for the future removal of page structure fields.

 - The series "mm/damon: add support for hugepage_size DAMOS filter"
   from Usama Arif adds a DAMOS filter which permits the filtering by
   huge page sizes.

 - The series "mm: permit guard regions for file-backed/shmem mappings"
   from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state. The feature now covers shmem and
   file-backed mappings.

 - The series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping
   for pte-mapped large folios.

 - The series "reimplement per-vma lock as a refcount" from Suren
   Baghdasaryan puts the vm_lock back into the vma. Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy. This patchset provides small (0-10%) improvements on one
   microbenchmark.

 - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
   improves" from SeongJae Park does some maintenance work on the DAMON
   docs.

 - The series "hugetlb/CMA improvements for large systems" from Frank
   van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.

 - The series "mm/damon: introduce DAMOS filter type for unmapped pages"
   from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.

 - The series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.

 - The series "selftests/mm: Some cleanups from trying to run them" from
   Brendan Jackman fixes a pile of unrelated issues which Brendan
   encountered while runnimg our selftests.

 - The series "fs/proc/task_mmu: add guard region bit to pagemap" from
   Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.

 - The series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply
   wasn't being effective.

 - The series "mm: cleanups for device-exclusive entries (hmm)" from
   David Hildenbrand implements a number of unrelated cleanups in this
   code.

 - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
   implements a number of preparatoty cleanups to the GENERIC_PTDUMP
   Kconfig logic.

 - The series "mm/damon: auto-tune aggregation interval" from SeongJae
   Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.

 - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
   powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
   preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.

 - The series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the
   code easier to follow.

 - The series "page_counter cleanup and size reduction" from Shakeel
   Butt cleans up the page_counter code and fixes a size increase which
   we accidentally added late last year.

 - The series "Add a command line option that enables control of how
   many threads should be used to allocate huge pages" from Thomas
   Prescher does that. It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.

 - The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
   from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.

 - The series "mm/damon: make allow filters after reject filters useful
   and intuitive" from SeongJae Park improves the handling of allow and
   reject filters. Behaviour is made more consistent and the documention
   is updated accordingly.

 - The series "Switch zswap to object read/write APIs" from Yosry Ahmed
   updates zswap to the new object read/write APIs and thus permits the
   removal of some legacy code from zpool and zsmalloc.

 - The series "Some trivial cleanups for shmem" from Baolin Wang does as
   it claims.

 - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
   Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.

 - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
   preparatoty refactoring and cleanup of the mremap() code.

 - The series "mm: MM owner tracking for large folios (!hugetlb) +
   CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.

 - The series "mm/damon: add sysfs dirs for managing DAMOS filters based
   on handling layers" from SeongJae Park adds a couple of new sysfs
   directories to ease the management of DAMON/DAMOS filters.

 - The series "arch, mm: reduce code duplication in mem_init()" from
   Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.

 - The series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.

 - The series "mm: page_ext: Introduce new iteration API" from Luiz
   Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.

 - The series "Buddy allocator like (or non-uniform) folio split" from
   Zi Yan reworks the code to split a folio into smaller folios. The
   main benefit is lessened memory consumption: fewer post-split folios
   are generated.

 - The series "Minimize xa_node allocation during xarry split" from Zi
   Yan reduces the number of xarray xa_nodes which are generated during
   an xarray split.

 - The series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.

 - The series "Add tracepoints for lowmem reserves, watermarks and
   totalreserve_pages" from Martin Liu adds some more tracepoints to the
   page allocator code.

 - The series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which
   SeongJae observed during his earlier madvise work.

 - The series "mm/hwpoison: Fix regressions in memory failure handling"
   from Shuai Xue addresses two quite serious regressions which Shuai
   has observed in the memory-failure implementation.

 - The series "mm: reliable huge page allocator" from Johannes Weiner
   makes huge page allocations cheaper and more reliable by reducing
   fragmentation.

 - The series "Minor memcg cleanups & prep for memdescs" from Matthew
   Wilcox is preparatory work for the future implementation of memdescs.

 - The series "track memory used by balloon drivers" from Nico Pache
   introduces a way to track memory used by our various balloon drivers.

 - The series "mm/damon: introduce DAMOS filter type for active pages"
   from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.

 - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
   separates the proactive reclaim statistics from the direct reclaim
   statistics.

 - The series "mm/vmscan: don't try to reclaim hwpoison folio" from
   Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
   code.

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...
 2025-04-01 09:29:18 -07:00
David Hildenbrand
31a31da8a6 mm: move _pincount in folio to page[2] on 32bit 
Let's free up some space on 32bit in page[1] by moving the _pincount to
page[2].

For order-1 folios (never anon folios!) on 32bit, we will now also use the
GUP_PIN_COUNTING_BIAS approach.  A fully-mapped order-1 folio requires 2
references.  With GUP_PIN_COUNTING_BIAS being 1024, we'd detect such
folios as "maybe pinned" with 512 full mappings, instead of 1024 for
order-0.  As anon folios are out of the picture (which are the most
relevant users of checking for pinnings on *mapped* pages) and we are
talking about 32bit, this is not expected to cause any trouble.

In __dump_page(), copy one additional folio page if we detect a folio with
an order > 1, so we can dump the pincount on order > 1 folios reliably.

Note that THPs on 32bit are not particularly common (and we don't care too
much about performance), but we want to keep it working reliably, because
likely we want to use large folios there as well in the future,
independent of PMD leaf support.

Once we dynamically allocate "struct folio", fortunately the 32bit
specifics will likely go away again; even small folios could then have a
pincount and folio_has_pincount() would essentially always return "true".

Link: https://lkml.kernel.org/r/20250303163014.1128035-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-03-17 22:06:44 -07:00
Alistair Popple
38607c62b3 fs/dax: properly refcount fs dax pages 
Currently fs dax pages are considered free when the refcount drops to one
and their refcounts are not increased when mapped via PTEs or decreased
when unmapped.  This requires special logic in mm paths to detect that
these pages should not be properly refcounted, and to detect when the
refcount drops to one instead of zero.

On the other hand get_user_pages(), etc.  will properly refcount fs dax
pages by taking a reference and dropping it when the page is unpinned.

Tracking this special behaviour requires extra PTE bits (eg.  pte_devmap)
and introduces rules that are potentially confusing and specific to FS DAX
pages.  To fix this, and to possibly allow removal of the special PTE bits
in future, convert the fs dax page refcounts to be zero based and instead
take a reference on the page each time it is mapped as is currently the
case for normal pages.

This may also allow a future clean-up to remove the pgmap refcounting that
is currently done in mm/gup.c.

Link: https://lkml.kernel.org/r/c7d886ad7468a20452ef6e0ddab6cfe220874e7c.1740713401.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Asahi Lina <lina@asahilina.net>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-03-17 22:06:41 -07:00
Alistair Popple
a58c6fb662 mm/gup: remove redundant check for PCI P2PDMA page 
PCI P2PDMA pages are not mapped with pXX_devmap PTEs therefore the check
in __gup_device_huge() is redundant.  Remove it

Link: https://lkml.kernel.org/r/260e3dcfaf05ff1c734a49698ed4332b5dae04c2.1740713401.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Dan Wiliams <dan.j.williams@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Asahi Lina <lina@asahilina.net>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-03-17 22:06:38 -07:00
David Laight
c2661f5fe8 mm: remove the access_ok() call from gup_fast_fallback() 
Historiaclly the code relied on access_ok() to validate the address range.
Commit 26f4c32807 added an explicit wrap check before access_ok().
Commit c28b1fc703 then changed the wrap test to use check_add_overflow().
Commit 6014bc2756 relaxed the checks in x86-64's access_ok() and added
  an explicit check for TASK_SIZE here to make up for it.
That left a pointless access_ok() call with its associated 'lfence' that
can never actually fail.

So just delete the test.

Link: https://lkml.kernel.org/r/20250209174711.60889-1-david.laight.linux@gmail.com
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-03-16 22:06:10 -07:00
David Hildenbrand
8977752c80 mm/gup: reject FOLL_SPLIT_PMD with hugetlb VMAs 
Patch series "mm: fixes for device-exclusive entries (hmm)", v2.

Discussing the PageTail() call in make_device_exclusive_range() with
Willy, I recently discovered [1] that device-exclusive handling does not
properly work with THP, making the hmm-tests selftests fail if THPs are
enabled on the system.

Looking into more details, I found that hugetlb is not properly fenced,
and I realized that something that was bugging me for longer -- how
device-exclusive entries interact with mapcounts -- completely breaks
migration/swapout/split/hwpoison handling of these folios while they have
device-exclusive PTEs.

The program below can be used to allocate 1 GiB worth of pages and making
them device-exclusive on a kernel with CONFIG_TEST_HMM.

Once they are device-exclusive, these folios cannot get swapped out
(proc$pid/smaps_rollup will always indicate 1 GiB RSS no matter how much
one forces memory reclaim), and when having a memory block onlined to
ZONE_MOVABLE, trying to offline it will loop forever and complain about
failed migration of a page that should be movable.

# echo offline > /sys/devices/system/memory/memory136/state
# echo online_movable > /sys/devices/system/memory/memory136/state
# ./hmm-swap &
... wait until everything is device-exclusive
# echo offline > /sys/devices/system/memory/memory136/state
[  285.193431][T14882] page: refcount:2 mapcount:0 mapping:0000000000000000
  index:0x7f20671f7 pfn:0x442b6a
[  285.196618][T14882] memcg:ffff888179298000
[  285.198085][T14882] anon flags: 0x5fff0000002091c(referenced|uptodate|
  dirty|active|owner_2|swapbacked|node=1|zone=3|lastcpupid=0x7ff)
[  285.201734][T14882] raw: ...
[  285.204464][T14882] raw: ...
[  285.207196][T14882] page dumped because: migration failure
[  285.209072][T14882] page_owner tracks the page as allocated
[  285.210915][T14882] page last allocated via order 0, migratetype
  Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO),
  id 14926, tgid 14926 (hmm-swap), ts 254506295376, free_ts 227402023774
[  285.216765][T14882]  post_alloc_hook+0x197/0x1b0
[  285.218874][T14882]  get_page_from_freelist+0x76e/0x3280
[  285.220864][T14882]  __alloc_frozen_pages_noprof+0x38e/0x2740
[  285.223302][T14882]  alloc_pages_mpol+0x1fc/0x540
[  285.225130][T14882]  folio_alloc_mpol_noprof+0x36/0x340
[  285.227222][T14882]  vma_alloc_folio_noprof+0xee/0x1a0
[  285.229074][T14882]  __handle_mm_fault+0x2b38/0x56a0
[  285.230822][T14882]  handle_mm_fault+0x368/0x9f0
...

This series fixes all issues I found so far.  There is no easy way to fix
without a bigger rework/cleanup.  I have a bunch of cleanups on top (some
previous sent, some the result of the discussion in v1) that I will send
out separately once this landed and I get to it.

I wish we could just use some special present PROT_NONE PTEs instead of
these (non-present, non-none) fake-swap entries; but that just results in
the same problem we keep having (lack of spare PTE bits), and staring at
other similar fake-swap entries, that ship has sailed.

With this series, make_device_exclusive() doesn't actually belong into
mm/rmap.c anymore, but I'll leave moving that for another day.

I only tested this series with the hmm-tests selftests due to lack of HW,
so I'd appreciate some testing, especially if the interaction between two
GPUs wanting a device-exclusive entry works as expected.

<program>
#include <stdio.h>
#include <fcntl.h>
#include <stdint.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/ioctl.h>

#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)

struct hmm_dmirror_cmd {
	__u64 addr;
	__u64 ptr;
	__u64 npages;
	__u64 cpages;
	__u64 faults;
};

const size_t size = 1 * 1024 * 1024 * 1024ul;
const size_t chunk_size = 2 * 1024 * 1024ul;

int main(void)
{
	struct hmm_dmirror_cmd cmd;
	size_t cur_size;
	int fd, ret;
	char *addr, *mirror;

	fd = open("/dev/hmm_dmirror1", O_RDWR, 0);
	if (fd < 0) {
		perror("open failed\n");
		exit(1);
	}

	addr = mmap(NULL, size, PROT_READ | PROT_WRITE,
		    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
	if (addr == MAP_FAILED) {
		perror("mmap failed\n");
		exit(1);
	}
	madvise(addr, size, MADV_NOHUGEPAGE);
	memset(addr, 1, size);

	mirror = malloc(chunk_size);

	for (cur_size = 0; cur_size < size; cur_size += chunk_size) {
		cmd.addr = (uintptr_t)addr + cur_size;
		cmd.ptr = (uintptr_t)mirror;
		cmd.npages = chunk_size / getpagesize();
		ret = ioctl(fd, HMM_DMIRROR_EXCLUSIVE, &cmd);
		if (ret) {
			perror("ioctl failed\n");
			exit(1);
		}
	}
	pause();
	return 0;
}
</program>

[1] https://lkml.kernel.org/r/25e02685-4f1d-47fa-be5b-01ff85bb0ce2@redhat.com


This patch (of 17):

We only have two FOLL_SPLIT_PMD users.  While uprobe refuses hugetlb
early, make_device_exclusive_range() can end up getting called on hugetlb
VMAs.

Right now, this means that with a PMD-sized hugetlb page, we can end up
calling split_huge_pmd(), because pmd_trans_huge() also succeeds with
hugetlb PMDs.

For example, using a modified hmm-test selftest one can trigger:

[  207.017134][T14945] ------------[ cut here ]------------
[  207.018614][T14945] kernel BUG at mm/page_table_check.c:87!
[  207.019716][T14945] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
[  207.021072][T14945] CPU: 3 UID: 0 PID: ...
[  207.023036][T14945] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
[  207.024834][T14945] RIP: 0010:page_table_check_clear.part.0+0x488/0x510
[  207.026128][T14945] Code: ...
[  207.029965][T14945] RSP: 0018:ffffc9000cb8f348 EFLAGS: 00010293
[  207.031139][T14945] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff8249a0cd
[  207.032649][T14945] RDX: ffff88811e883c80 RSI: ffffffff8249a357 RDI: ffff88811e883c80
[  207.034183][T14945] RBP: ffff888105c0a050 R08: 0000000000000005 R09: 0000000000000000
[  207.035688][T14945] R10: 00000000ffffffff R11: 0000000000000003 R12: 0000000000000001
[  207.037203][T14945] R13: 0000000000000200 R14: 0000000000000001 R15: dffffc0000000000
[  207.038711][T14945] FS:  00007f2783275740(0000) GS:ffff8881f4980000(0000) knlGS:0000000000000000
[  207.040407][T14945] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  207.041660][T14945] CR2: 00007f2782c00000 CR3: 0000000132356000 CR4: 0000000000750ef0
[  207.043196][T14945] PKRU: 55555554
[  207.043880][T14945] Call Trace:
[  207.044506][T14945]  <TASK>
[  207.045086][T14945]  ? __die+0x51/0x92
[  207.045864][T14945]  ? die+0x29/0x50
[  207.046596][T14945]  ? do_trap+0x250/0x320
[  207.047430][T14945]  ? do_error_trap+0xe7/0x220
[  207.048346][T14945]  ? page_table_check_clear.part.0+0x488/0x510
[  207.049535][T14945]  ? handle_invalid_op+0x34/0x40
[  207.050494][T14945]  ? page_table_check_clear.part.0+0x488/0x510
[  207.051681][T14945]  ? exc_invalid_op+0x2e/0x50
[  207.052589][T14945]  ? asm_exc_invalid_op+0x1a/0x20
[  207.053596][T14945]  ? page_table_check_clear.part.0+0x1fd/0x510
[  207.054790][T14945]  ? page_table_check_clear.part.0+0x487/0x510
[  207.055993][T14945]  ? page_table_check_clear.part.0+0x488/0x510
[  207.057195][T14945]  ? page_table_check_clear.part.0+0x487/0x510
[  207.058384][T14945]  __page_table_check_pmd_clear+0x34b/0x5a0
[  207.059524][T14945]  ? __pfx___page_table_check_pmd_clear+0x10/0x10
[  207.060775][T14945]  ? __pfx___mutex_unlock_slowpath+0x10/0x10
[  207.061940][T14945]  ? __pfx___lock_acquire+0x10/0x10
[  207.062967][T14945]  pmdp_huge_clear_flush+0x279/0x360
[  207.064024][T14945]  split_huge_pmd_locked+0x82b/0x3750
...

Before commit 9cb28da546 ("mm/gup: handle hugetlb in the generic
follow_page_mask code"), we would have ignored the flag; instead, let's
simply refuse the combination completely in check_vma_flags(): the caller
is likely not prepared to handle any hugetlb folios.

We'll teach make_device_exclusive_range() separately to ignore any hugetlb
folios as a future-proof safety net.

Link: https://lkml.kernel.org/r/20250210193801.781278-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250210193801.781278-2-david@redhat.com
Fixes: 9cb28da546 ("mm/gup: handle hugetlb in the generic follow_page_mask code")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lyude <lyude@redhat.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yanteng Si <si.yanteng@linux.dev>
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-03-16 22:05:57 -07:00
Mateusz Guzik
d6ff4c8f65
fs: avoid mmap sem relocks when coredumping with many missing pages 
Dumping processes with large allocated and mostly not-faulted areas is
very slow.

Borrowing a test case from Tavian Barnes:

int main(void) {
    char *mem = mmap(NULL, 1ULL << 40, PROT_READ | PROT_WRITE,
            MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
    printf("%p %m\n", mem);
    if (mem != MAP_FAILED) {
            mem[0] = 1;
    }
    abort();
}

That's 1TB of almost completely not-populated area.

On my test box it takes 13-14 seconds to dump.

The profile shows:
-   99.89%     0.00%  a.out
     entry_SYSCALL_64_after_hwframe
     do_syscall_64
     syscall_exit_to_user_mode
     arch_do_signal_or_restart
   - get_signal
      - 99.89% do_coredump
         - 99.88% elf_core_dump
            - dump_user_range
               - 98.12% get_dump_page
                  - 64.19% __get_user_pages
                     - 40.92% gup_vma_lookup
                        - find_vma
                           - mt_find
                                4.21% __rcu_read_lock
                                1.33% __rcu_read_unlock
                     - 3.14% check_vma_flags
                          0.68% vma_is_secretmem
                       0.61% __cond_resched
                       0.60% vma_pgtable_walk_end
                       0.59% vma_pgtable_walk_begin
                       0.58% no_page_table
                  - 15.13% down_read_killable
                       0.69% __cond_resched
                    13.84% up_read
                 0.58% __cond_resched

Almost 29% of the time is spent relocking the mmap semaphore between
calls to get_dump_page() which find nothing.

Whacking that results in times of 10 seconds (down from 13-14).

While here make the thing killable.

The real problem is the page-sized iteration and the real fix would
patch it up instead. It is left as an exercise for the mm-familiar
reader.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250119103205.2172432-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
 2025-02-21 10:25:32 +01:00
Zhaoyang Huang
1aaf8c1229 mm: gup: fix infinite loop within __get_longterm_locked 
We can run into an infinite loop in __get_longterm_locked() when
collect_longterm_unpinnable_folios() finds only folios that are isolated
from the LRU or were never added to the LRU.  This can happen when all
folios to be pinned are never added to the LRU, for example when
vm_ops->fault allocated pages using cma_alloc() and never added them to
the LRU.

Fix it by simply taking a look at the list in the single caller, to see if
anything was added.

[zhaoyang.huang@unisoc.com: move definition of local]
  Link: https://lkml.kernel.org/r/20250122012604.3654667-1-zhaoyang.huang@unisoc.com
Link: https://lkml.kernel.org/r/20250121020159.3636477-1-zhaoyang.huang@unisoc.com
Fixes: 67e139b02d ("mm/gup.c: refactor check_and_migrate_movable_pages()")
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Aijun Sun <aijun.sun@unisoc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-02-01 03:53:27 -08:00
Linus Torvalds
9c5968db9e The various patchsets are summarized below. Plus of course many 
indivudual patches which are described in their changelogs.
 
 - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the
   page allocator so we end up with the ability to allocate and free
   zero-refcount pages.  So that callers (ie, slab) can avoid a refcount
   inc & dec.
 
 - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use
   large folios other than PMD-sized ones.
 
 - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and
   fixes for this small built-in kernel selftest.
 
 - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of
   the mapletree code.
 
 - "mm: fix format issues and param types" from Keren Sun implements a
   few minor code cleanups.
 
 - "simplify split calculation" from Wei Yang provides a few fixes and a
   test for the mapletree code.
 
 - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes
   continues the work of moving vma-related code into the (relatively) new
   mm/vma.c.
 
 - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
   Hildenbrand cleans up and rationalizes handling of gfp flags in the page
   allocator.
 
 - "readahead: Reintroduce fix for improper RA window sizing" from Jan
   Kara is a second attempt at fixing a readahead window sizing issue.  It
   should reduce the amount of unnecessary reading.
 
 - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
   addresses an issue where "huge" amounts of pte pagetables are
   accumulated
   (https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/).
   Qi's series addresses this windup by synchronously freeing PTE memory
   within the context of madvise(MADV_DONTNEED).
 
 - "selftest/mm: Remove warnings found by adding compiler flags" from
   Muhammad Usama Anjum fixes some build warnings in the selftests code
   when optional compiler warnings are enabled.
 
 - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David
   Hildenbrand tightens the allocator's observance of __GFP_HARDWALL.
 
 - "pkeys kselftests improvements" from Kevin Brodsky implements various
   fixes and cleanups in the MM selftests code, mainly pertaining to the
   pkeys tests.
 
 - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
   estimate application working set size.
 
 - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
   provides some cleanups to memcg's hugetlb charging logic.
 
 - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
   removes the global swap cgroup lock.  A speedup of 10% for a tmpfs-based
   kernel build was demonstrated.
 
 - "zram: split page type read/write handling" from Sergey Senozhatsky
   has several fixes and cleaups for zram in the area of zram_write_page().
   A watchdog softlockup warning was eliminated.
 
 - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky
   cleans up the pagetable destructor implementations.  A rare
   use-after-free race is fixed.
 
 - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
   simplifies and cleans up the debugging code in the VMA merging logic.
 
 - "Account page tables at all levels" from Kevin Brodsky cleans up and
   regularizes the pagetable ctor/dtor handling.  This results in
   improvements in accounting accuracy.
 
 - "mm/damon: replace most damon_callback usages in sysfs with new core
   functions" from SeongJae Park cleans up and generalizes DAMON's sysfs
   file interface logic.
 
 - "mm/damon: enable page level properties based monitoring" from
   SeongJae Park increases the amount of information which is presented in
   response to DAMOS actions.
 
 - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes
   DAMON's long-deprecated debugfs interfaces.  Thus the migration to sysfs
   is completed.
 
 - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter
   Xu cleans up and generalizes the hugetlb reservation accounting.
 
 - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
   removes a never-used feature of the alloc_pages_bulk() interface.
 
 - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
   extends DAMOS filters to support not only exclusion (rejecting), but
   also inclusion (allowing) behavior.
 
 - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
   "introduces a new memory descriptor for zswap.zpool that currently
   overlaps with struct page for now.  This is part of the effort to reduce
   the size of struct page and to enable dynamic allocation of memory
   descriptors."
 
 - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and
   simplifies the swap allocator locking.  A speedup of 400% was
   demonstrated for one workload.  As was a 35% reduction for kernel build
   time with swap-on-zram.
 
 - "mm: update mips to use do_mmap(), make mmap_region() internal" from
   Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
   mmap_region() can be made MM-internal.
 
 - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU
   regressions and otherwise improves MGLRU performance.
 
 - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park
   updates DAMON documentation.
 
 - "Cleanup for memfd_create()" from Isaac Manjarres does that thing.
 
 - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand
   provides various cleanups in the areas of hugetlb folios, THP folios and
   migration.
 
 - "Uncached buffered IO" from Jens Axboe implements the new
   RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache
   reading and writing.  To permite userspace to address issues with
   massive buildup of useless pagecache when reading/writing fast devices.
 
 - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
   Weißschuh fixes and optimizes some of the MM selftests.
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Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...
 2025-01-26 18:36:23 -08:00
David Hildenbrand
4c640f1280 mm/hugetlb: rename isolate_hugetlb() to folio_isolate_hugetlb() 
Let's make the function name match "folio_isolate_lru()", and add some
kernel doc.

Link: https://lkml.kernel.org/r/20250113131611.2554758-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-01-25 20:22:41 -08:00
Linus Torvalds
6c4aa896eb Performance events changes for v6.14: 
- Seqlock optimizations that arose in a perf context and were
    merged into the perf tree:
 
    - seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
    - mm: Convert mm_lock_seq to a proper seqcount ((Suren Baghdasaryan)
    - mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren Baghdasaryan)
    - mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)
 
  - Core perf enhancements:
 
    - Reduce 'struct page' footprint of perf by mapping pages
      in advance (Lorenzo Stoakes)
    - Save raw sample data conditionally based on sample type (Yabin Cui)
    - Reduce sampling overhead by checking sample_type in
      perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin Cui)
    - Export perf_exclude_event() (Namhyung Kim)
 
  - Uprobes scalability enhancements: (Andrii Nakryiko)
 
    - Simplify find_active_uprobe_rcu() VMA checks
    - Add speculative lockless VMA-to-inode-to-uprobe resolution
    - Simplify session consumer tracking
    - Decouple return_instance list traversal and freeing
    - Ensure return_instance is detached from the list before freeing
    - Reuse return_instances between multiple uretprobes within task
    - Guard against kmemdup() failing in dup_return_instance()
 
  - AMD core PMU driver enhancements:
 
    - Relax privilege filter restriction on AMD IBS (Namhyung Kim)
 
  - AMD RAPL energy counters support: (Dhananjay Ugwekar)
 
    - Introduce topology_logical_core_id() (K Prateek Nayak)
 
    - Remove the unused get_rapl_pmu_cpumask() function
    - Remove the cpu_to_rapl_pmu() function
    - Rename rapl_pmu variables
    - Make rapl_model struct global
    - Add arguments to the init and cleanup functions
    - Modify the generic variable names to *_pkg*
    - Remove the global variable rapl_msrs
    - Move the cntr_mask to rapl_pmus struct
    - Add core energy counter support for AMD CPUs
 
  - Intel core PMU driver enhancements:
 
    - Support RDPMC 'metrics clear mode' feature (Kan Liang)
    - Clarify adaptive PEBS processing (Kan Liang)
    - Factor out functions for PEBS records processing (Kan Liang)
    - Simplify the PEBS records processing for adaptive PEBS (Kan Liang)
 
  - Intel uncore driver enhancements: (Kan Liang)
 
    - Convert buggy pmu->func_id use to pmu->registered
    - Support more units on Granite Rapids
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "Seqlock optimizations that arose in a perf context and were merged
  into the perf tree:

   - seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
   - mm: Convert mm_lock_seq to a proper seqcount (Suren Baghdasaryan)
   - mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren
     Baghdasaryan)
   - mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)

  Core perf enhancements:

   - Reduce 'struct page' footprint of perf by mapping pages in advance
     (Lorenzo Stoakes)
   - Save raw sample data conditionally based on sample type (Yabin Cui)
   - Reduce sampling overhead by checking sample_type in
     perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin
     Cui)
   - Export perf_exclude_event() (Namhyung Kim)

  Uprobes scalability enhancements: (Andrii Nakryiko)

   - Simplify find_active_uprobe_rcu() VMA checks
   - Add speculative lockless VMA-to-inode-to-uprobe resolution
   - Simplify session consumer tracking
   - Decouple return_instance list traversal and freeing
   - Ensure return_instance is detached from the list before freeing
   - Reuse return_instances between multiple uretprobes within task
   - Guard against kmemdup() failing in dup_return_instance()

  AMD core PMU driver enhancements:

   - Relax privilege filter restriction on AMD IBS (Namhyung Kim)

  AMD RAPL energy counters support: (Dhananjay Ugwekar)

   - Introduce topology_logical_core_id() (K Prateek Nayak)
   - Remove the unused get_rapl_pmu_cpumask() function
   - Remove the cpu_to_rapl_pmu() function
   - Rename rapl_pmu variables
   - Make rapl_model struct global
   - Add arguments to the init and cleanup functions
   - Modify the generic variable names to *_pkg*
   - Remove the global variable rapl_msrs
   - Move the cntr_mask to rapl_pmus struct
   - Add core energy counter support for AMD CPUs

  Intel core PMU driver enhancements:

   - Support RDPMC 'metrics clear mode' feature (Kan Liang)
   - Clarify adaptive PEBS processing (Kan Liang)
   - Factor out functions for PEBS records processing (Kan Liang)
   - Simplify the PEBS records processing for adaptive PEBS (Kan Liang)

  Intel uncore driver enhancements: (Kan Liang)

   - Convert buggy pmu->func_id use to pmu->registered
   - Support more units on Granite Rapids"

* tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  perf: map pages in advance
  perf/x86/intel/uncore: Support more units on Granite Rapids
  perf/x86/intel/uncore: Clean up func_id
  perf/x86/intel: Support RDPMC metrics clear mode
  uprobes: Guard against kmemdup() failing in dup_return_instance()
  perf/x86: Relax privilege filter restriction on AMD IBS
  perf/core: Export perf_exclude_event()
  uprobes: Reuse return_instances between multiple uretprobes within task
  uprobes: Ensure return_instance is detached from the list before freeing
  uprobes: Decouple return_instance list traversal and freeing
  uprobes: Simplify session consumer tracking
  uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
  uprobes: simplify find_active_uprobe_rcu() VMA checks
  mm: introduce mmap_lock_speculate_{try_begin|retry}
  mm: convert mm_lock_seq to a proper seqcount
  mm/gup: Use raw_seqcount_try_begin()
  seqlock: add raw_seqcount_try_begin
  perf/x86/rapl: Add core energy counter support for AMD CPUs
  perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
  perf/x86/rapl: Remove the global variable rapl_msrs
  ...
 2025-01-21 10:52:03 -08:00
Guillaume Morin
052ccfbcc6 mm/hugetlb: support FOLL_FORCE|FOLL_WRITE 
Eric reported that PTRACE_POKETEXT fails when applications use hugetlb for
mapping text using huge pages.  Before commit 1d8d14641f ("mm/hugetlb:
support write-faults in shared mappings"), PTRACE_POKETEXT worked by
accident, but it was buggy and silently ended up mapping pages writable
into the page tables even though VM_WRITE was not set.

In general, FOLL_FORCE|FOLL_WRITE does currently not work with hugetlb. 
Let's implement FOLL_FORCE|FOLL_WRITE properly for hugetlb, such that what
used to work in the past by accident now properly works, allowing
applications using hugetlb for text etc.  to get properly debugged.

This change might also be required to implement uprobes support for
hugetlb [1].

[1] https://lore.kernel.org/lkml/ZiK50qob9yl5e0Xz@bender.morinfr.org/

Link: https://lkml.kernel.org/r/Z1NshNfWuzUCPebA@bender.morinfr.org
Signed-off-by: Guillaume Morin <guillaume@morinfr.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Hagberg <ehagberg@janestreet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2025-01-13 22:40:51 -08:00
John Hubbard
a1268be280 mm/gup: handle NULL pages in unpin_user_pages() 
The recent addition of "pofs" (pages or folios) handling to gup has a
flaw: it assumes that unpin_user_pages() handles NULL pages in the pages**
array.  That's not the case, as I discovered when I ran on a new
configuration on my test machine.

Fix this by skipping NULL pages in unpin_user_pages(), just like
unpin_folios() already does.

Details: when booting on x86 with "numa=fake=2 movablecore=4G" on Linux
6.12, and running this:

    tools/testing/selftests/mm/gup_longterm

...I get the following crash:

BUG: kernel NULL pointer dereference, address: 0000000000000008
RIP: 0010:sanity_check_pinned_pages+0x3a/0x2d0
...
Call Trace:
 <TASK>
 ? __die_body+0x66/0xb0
 ? page_fault_oops+0x30c/0x3b0
 ? do_user_addr_fault+0x6c3/0x720
 ? irqentry_enter+0x34/0x60
 ? exc_page_fault+0x68/0x100
 ? asm_exc_page_fault+0x22/0x30
 ? sanity_check_pinned_pages+0x3a/0x2d0
 unpin_user_pages+0x24/0xe0
 check_and_migrate_movable_pages_or_folios+0x455/0x4b0
 __gup_longterm_locked+0x3bf/0x820
 ? mmap_read_lock_killable+0x12/0x50
 ? __pfx_mmap_read_lock_killable+0x10/0x10
 pin_user_pages+0x66/0xa0
 gup_test_ioctl+0x358/0xb20
 __se_sys_ioctl+0x6b/0xc0
 do_syscall_64+0x7b/0x150
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Link: https://lkml.kernel.org/r/20241121034933.77502-1-jhubbard@nvidia.com
Fixes: 94efde1d15 ("mm/gup: avoid an unnecessary allocation call for FOLL_LONGTERM cases")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Junxiao Chang <junxiao.chang@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-12-05 19:54:42 -08:00
Peter Zijlstra
7528585290 mm/gup: Use raw_seqcount_try_begin() 
David pointed out that gup_fast() does exactly what the new
raw_seqcount_try_begin() does -- use it.

Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
 2024-12-02 12:01:37 +01:00
Linus Torvalds
5c00ff742b - The series "zram: optimal post-processing target selection" from 
Sergey Senozhatsky improves zram's post-processing selection algorithm.
   This leads to improved memory savings.
 
 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
 
 	- "refine mas_mab_cp()"
 	- "Reduce the space to be cleared for maple_big_node"
 	- "maple_tree: simplify mas_push_node()"
 	- "Following cleanup after introduce mas_wr_store_type()"
 	- "refine storing null"
 
 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.
 
 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping code.
 
 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of shadow
   entries.
 
 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.
 
 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in the
   hugetlb code.
 
 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page into
   small pages.  Instead we replace the whole thing with a THP.  More
   consistent cleaner and potentiall saves a large number of pagefaults.
 
 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.
 
 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to do.
 
 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio size
   rather than as individual pages.  A 20% speedup was observed.
 
 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting.
 
 - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt
   removes the long-deprecated memcgv2 charge moving feature.
 
 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.
 
 - The series "x86/module: use large ROX pages for text allocations" from
   Mike Rapoport teaches x86 to use large pages for read-only-execute
   module text.
 
 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.
 
 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/.  A slow march towards shrinking
   struct page.
 
 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.
 
 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression.  It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.
 
 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests
   over to the KUnit framework.
 
 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a single
   VMA, rather than requiring that multiple VMAs be created for this.
   Improved efficiencies for userspace memory allocators are expected.
 
 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.
 
 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.
 
 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP from
   the kernel boot command line.
 
 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.
 
 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep is
   enabled.
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Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
 2024-11-23 09:58:07 -08:00
Linus Torvalds
341d041daa iommufd 6.13 merge window pull 
Several new features and uAPI for iommufd:
 
 - IOMMU_IOAS_MAP_FILE allows passing in a file descriptor as the backing
   memory for an iommu mapping. To date VFIO/iommufd have used VMA's and
   pin_user_pages(), this now allows using memfds and memfd_pin_folios().
   Notably this creates a pure folio path from the memfd to the iommu page
   table where memory is never broken down to PAGE_SIZE.
 
 - IOMMU_IOAS_CHANGE_PROCESS moves the pinned page accounting between two
   processes. Combined with the above this allows iommufd to support a VMM
   re-start using exec() where something like qemu would exec() a new
   version of itself and fd pass the memfds/iommufd/etc to the new
   process. The memfd allows DMA access to the memory to continue while
   the new process is getting setup, and the CHANGE_PROCESS updates all
   the accounting.
 
 - Support for fault reporting to userspace on non-PRI HW, such as ARM
   stall-mode embedded devices.
 
 - IOMMU_VIOMMU_ALLOC introduces the concept of a HW/driver backed virtual
   iommu. This will be used by VMMs to access hardware features that are
   contained with in a VM. The first use is to inform the kernel of the
   virtual SID to physical SID mapping when issuing SID based invalidation
   on ARM. Further uses will tie HW features that are directly accessed by
   the VM, such as invalidation queue assignment and others.
 
 - IOMMU_VDEVICE_ALLOC informs the kernel about the mapping of virtual
   device to physical device within a VIOMMU. Minimially this is used to
   translate VM issued cache invalidation commands from virtual to physical
   device IDs.
 
 - Enhancements to IOMMU_HWPT_INVALIDATE and IOMMU_HWPT_ALLOC to work with
   the VIOMMU
 
 - ARM SMMuv3 support for nested translation. Using the VIOMMU and VDEVICE
   the driver can model this HW's behavior for nested translation. This
   includes a shared branch from Will.
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "Several new features and uAPI for iommufd:

   - IOMMU_IOAS_MAP_FILE allows passing in a file descriptor as the
     backing memory for an iommu mapping. To date VFIO/iommufd have used
     VMA's and pin_user_pages(), this now allows using memfds and
     memfd_pin_folios(). Notably this creates a pure folio path from the
     memfd to the iommu page table where memory is never broken down to
     PAGE_SIZE.

   - IOMMU_IOAS_CHANGE_PROCESS moves the pinned page accounting between
     two processes. Combined with the above this allows iommufd to
     support a VMM re-start using exec() where something like qemu would
     exec() a new version of itself and fd pass the memfds/iommufd/etc
     to the new process. The memfd allows DMA access to the memory to
     continue while the new process is getting setup, and the
     CHANGE_PROCESS updates all the accounting.

   - Support for fault reporting to userspace on non-PRI HW, such as ARM
     stall-mode embedded devices.

   - IOMMU_VIOMMU_ALLOC introduces the concept of a HW/driver backed
     virtual iommu. This will be used by VMMs to access hardware
     features that are contained with in a VM. The first use is to
     inform the kernel of the virtual SID to physical SID mapping when
     issuing SID based invalidation on ARM. Further uses will tie HW
     features that are directly accessed by the VM, such as invalidation
     queue assignment and others.

   - IOMMU_VDEVICE_ALLOC informs the kernel about the mapping of virtual
     device to physical device within a VIOMMU. Minimially this is used
     to translate VM issued cache invalidation commands from virtual to
     physical device IDs.

   - Enhancements to IOMMU_HWPT_INVALIDATE and IOMMU_HWPT_ALLOC to work
     with the VIOMMU

   - ARM SMMuv3 support for nested translation. Using the VIOMMU and
     VDEVICE the driver can model this HW's behavior for nested
     translation. This includes a shared branch from Will"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (51 commits)
  iommu/arm-smmu-v3: Import IOMMUFD module namespace
  iommufd: IOMMU_IOAS_CHANGE_PROCESS selftest
  iommufd: Add IOMMU_IOAS_CHANGE_PROCESS
  iommufd: Lock all IOAS objects
  iommufd: Export do_update_pinned
  iommu/arm-smmu-v3: Support IOMMU_HWPT_INVALIDATE using a VIOMMU object
  iommu/arm-smmu-v3: Allow ATS for IOMMU_DOMAIN_NESTED
  iommu/arm-smmu-v3: Use S2FWB for NESTED domains
  iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED
  iommu/arm-smmu-v3: Support IOMMU_VIOMMU_ALLOC
  Documentation: userspace-api: iommufd: Update vDEVICE
  iommufd/selftest: Add vIOMMU coverage for IOMMU_HWPT_INVALIDATE ioctl
  iommufd/selftest: Add IOMMU_TEST_OP_DEV_CHECK_CACHE test command
  iommufd/selftest: Add mock_viommu_cache_invalidate
  iommufd/viommu: Add iommufd_viommu_find_dev helper
  iommu: Add iommu_copy_struct_from_full_user_array helper
  iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATE
  iommu/viommu: Add cache_invalidate to iommufd_viommu_ops
  iommufd/selftest: Add IOMMU_VDEVICE_ALLOC test coverage
  iommufd/viommu: Add IOMMUFD_OBJ_VDEVICE and IOMMU_VDEVICE_ALLOC ioctl
  ...
 2024-11-21 12:40:50 -08:00
John Hubbard
94efde1d15 mm/gup: avoid an unnecessary allocation call for FOLL_LONGTERM cases 
commit 53ba78de06 ("mm/gup: introduce
check_and_migrate_movable_folios()") created a new constraint on the
pin_user_pages*() API family: a potentially large internal allocation must
now occur, for FOLL_LONGTERM cases.

A user-visible consequence has now appeared: user space can no longer pin
more than 2GB of memory anymore on x86_64.  That's because, on a 4KB
PAGE_SIZE system, when user space tries to (indirectly, via a device
driver that calls pin_user_pages()) pin 2GB, this requires an allocation
of a folio pointers array of MAX_PAGE_ORDER size, which is the limit for
kmalloc().

In addition to the directly visible effect described above, there is also
the problem of adding an unnecessary allocation.  The **pages array
argument has already been allocated, and there is no need for a redundant
**folios array allocation in this case.

Fix this by avoiding the new allocation entirely.  This is done by
referring to either the original page[i] within **pages, or to the
associated folio.  Thanks to David Hildenbrand for suggesting this
approach and for providing the initial implementation (which I've tested
and adjusted slightly) as well.

[jhubbard@nvidia.com: whitespace tweak, per David]
  Link: https://lkml.kernel.org/r/131cf9c8-ebc0-4cbb-b722-22fa8527bf3c@nvidia.com
[jhubbard@nvidia.com: bypass pofs_get_folio(), per Oscar]
  Link: https://lkml.kernel.org/r/c1587c7f-9155-45be-bd62-1e36c0dd6923@nvidia.com
Link: https://lkml.kernel.org/r/20241105032944.141488-2-jhubbard@nvidia.com
Fixes: 53ba78de06 ("mm/gup: introduce check_and_migrate_movable_folios()")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Junxiao Chang <junxiao.chang@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-11-12 10:14:00 -08:00
Matthew Wilcox (Oracle)
f0327de706 gup: convert FOLL_TOUCH case in follow_page_pte() to folio 
We already have the folio here, so just use it, removing three hidden
calls to compound_head().

Link: https://lkml.kernel.org/r/20241002151403.1345296-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-11-06 20:11:08 -08:00
John Hubbard
aa6f8b2593 mm/gup: stop leaking pinned pages in low memory conditions 
If a driver tries to call any of the pin_user_pages*(FOLL_LONGTERM) family
of functions, and requests "too many" pages, then the call will
erroneously leave pages pinned.  This is visible in user space as an
actual memory leak.

Repro is trivial: just make enough pin_user_pages(FOLL_LONGTERM) calls to
exhaust memory.

The root cause of the problem is this sequence, within
__gup_longterm_locked():

    __get_user_pages_locked()
    rc = check_and_migrate_movable_pages()

...which gets retried in a loop.  The loop error handling is incomplete,
clearly due to a somewhat unusual and complicated tri-state error API. 
But anyway, if -ENOMEM, or in fact, any unexpected error is returned from
check_and_migrate_movable_pages(), then __gup_longterm_locked() happily
returns the error, while leaving the pages pinned.

In the failed case, which is an app that requests (via a device driver)
30720000000 bytes to be pinned, and then exits, I see this:

    $ grep foll /proc/vmstat
        nr_foll_pin_acquired 7502048
        nr_foll_pin_released 2048

And after applying this patch, it returns to balanced pins:

    $ grep foll /proc/vmstat
        nr_foll_pin_acquired 7502048
        nr_foll_pin_released 7502048

Note that the child routine, check_and_migrate_movable_folios(), avoids
this problem, by unpinning any folios in the **folios argument, before
returning an error.

Fix this by making check_and_migrate_movable_pages() behave in exactly the
same way as check_and_migrate_movable_folios(): unpin all pages in
**pages, before returning an error.

Also, documentation was an aggravating factor, so:

1) Consolidate the documentation for these two routines, now that they
have identical external behavior.

2) Rewrite the consolidated documentation:

    a) Clearly list the three return code cases, and what happens in
    each case.

    b) Mention that one of the cases unpins the pages or folios, before
    returning an error code.

Link: https://lkml.kernel.org/r/20241018223411.310331-1-jhubbard@nvidia.com
Fixes: 24a95998e9 ("mm/gup.c: simplify and fix check_and_migrate_movable_pages() return codes")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Shigeru Yoshida <syoshida@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-10-30 20:14:10 -07:00
Steve Sistare
a2ad1b8101 mm/gup: Add folio_add_pins() 
Export a function that adds pins to an already-pinned huge-page folio.
This allows any range of small pages within the folio to be unpinned later.
For example, pages pinned via memfd_pin_folios and modified by
folio_add_pins could be unpinned via unpin_user_page(s).

Link: https://patch.msgid.link/r/1729861919-234514-2-git-send-email-steven.sistare@oracle.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
 2024-10-28 13:24:23 -03:00
Steve Sistare
dc677b5f37 mm/hugetlb: simplify refs in memfd_alloc_folio 
The folio_try_get in memfd_alloc_folio is not necessary.  Delete it, and
delete the matching folio_put in memfd_pin_folios.  This also avoids
leaking a ref if the memfd_alloc_folio call to hugetlb_add_to_page_cache
fails.  That error path is also broken in a second way -- when its
folio_put causes the ref to become 0, it will implicitly call
free_huge_folio, but then the path *explicitly* calls free_huge_folio. 
Delete the latter.

This is a continuation of the fix
  "mm/hugetlb: fix memfd_pin_folios free_huge_pages leak"

[steven.sistare@oracle.com: remove explicit call to free_huge_folio(), per Matthew]
  Link: https://lkml.kernel.org/r/Zti-7nPVMcGgpcbi@casper.infradead.org
  Link: https://lkml.kernel.org/r/1725481920-82506-1-git-send-email-steven.sistare@oracle.com
Link: https://lkml.kernel.org/r/1725478868-61732-1-git-send-email-steven.sistare@oracle.com
Fixes: 89c1905d9c ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Suggested-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-26 14:01:44 -07:00
Steve Sistare
ce645b9fdc mm/gup: fix memfd_pin_folios alloc race panic 
If memfd_pin_folios tries to create a hugetlb page, but someone else
already did, then folio gets the value -EEXIST here:

        folio = memfd_alloc_folio(memfd, start_idx);
        if (IS_ERR(folio)) {
                ret = PTR_ERR(folio);
                if (ret != -EEXIST)
                        goto err;

then on the next trip through the "while start_idx" loop we panic here:

        if (folio) {
                folio_put(folio);

To fix, set the folio to NULL on error.

Link: https://lkml.kernel.org/r/1725373521-451395-6-git-send-email-steven.sistare@oracle.com
Fixes: 89c1905d9c ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-26 14:01:43 -07:00
Steve Sistare
c56b6f3d80 mm/hugetlb: fix memfd_pin_folios free_huge_pages leak 
memfd_pin_folios followed by unpin_folios fails to restore free_huge_pages
if the pages were not already faulted in, because the folio refcount for
pages created by memfd_alloc_folio never goes to 0.  memfd_pin_folios
needs another folio_put to undo the folio_try_get below:

memfd_alloc_folio()
  alloc_hugetlb_folio_nodemask()
    dequeue_hugetlb_folio_nodemask()
      dequeue_hugetlb_folio_node_exact()
        folio_ref_unfreeze(folio, 1);    ; adds 1 refcount
  folio_try_get()                        ; adds 1 refcount
  hugetlb_add_to_page_cache()            ; adds 512 refcount (on x86)

With the fix, after memfd_pin_folios + unpin_folios, the refcount for the
(unfaulted) page is 512, which is correct, as the refcount for a faulted
unpinned page is 513.

Link: https://lkml.kernel.org/r/1725373521-451395-3-git-send-email-steven.sistare@oracle.com
Fixes: 89c1905d9c ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-26 14:01:43 -07:00
Linus Torvalds
617a814f14 ALong with the usual shower of singleton patches, notable patch series in 
this pull request are:
 
 "Align kvrealloc() with krealloc()" from Danilo Krummrich.  Adds
 consistency to the APIs and behaviour of these two core allocation
 functions.  This also simplifies/enables Rustification.
 
 "Some cleanups for shmem" from Baolin Wang.  No functional changes - mode
 code reuse, better function naming, logic simplifications.
 
 "mm: some small page fault cleanups" from Josef Bacik.  No functional
 changes - code cleanups only.
 
 "Various memory tiering fixes" from Zi Yan.  A small fix and a little
 cleanup.
 
 "mm/swap: remove boilerplate" from Yu Zhao.  Code cleanups and
 simplifications and .text shrinkage.
 
 "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt.  This
 is a feature, it adds new feilds to /proc/vmstat such as
 
     $ grep kstack /proc/vmstat
     kstack_1k 3
     kstack_2k 188
     kstack_4k 11391
     kstack_8k 243
     kstack_16k 0
 
 which tells us that 11391 processes used 4k of stack while none at all
 used 16k.  Useful for some system tuning things, but partivularly useful
 for "the dynamic kernel stack project".
 
 "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
 Teaches kmemleak to detect leaksage of percpu memory.
 
 "mm: memcg: page counters optimizations" from Roman Gushchin.  "3
 independent small optimizations of page counters".
 
 "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
 Hildenbrand.  Improves PTE/PMD splitlock detection, makes powerpc/8xx work
 correctly by design rather than by accident.
 
 "mm: remove arch_make_page_accessible()" from David Hildenbrand.  Some
 folio conversions which make arch_make_page_accessible() unneeded.
 
 "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
 Cleans up and fixes our handling of the resetting of the cgroup/process
 peak-memory-use detector.
 
 "Make core VMA operations internal and testable" from Lorenzo Stoakes.
 Rationalizaion and encapsulation of the VMA manipulation APIs.  With a
 view to better enable testing of the VMA functions, even from a
 userspace-only harness.
 
 "mm: zswap: fixes for global shrinker" from Takero Funaki.  Fix issues in
 the zswap global shrinker, resulting in improved performance.
 
 "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao.  Fill in
 some missing info in /proc/zoneinfo.
 
 "mm: replace follow_page() by folio_walk" from David Hildenbrand.  Code
 cleanups and rationalizations (conversion to folio_walk()) resulting in
 the removal of follow_page().
 
 "improving dynamic zswap shrinker protection scheme" from Nhat Pham.  Some
 tuning to improve zswap's dynamic shrinker.  Significant reductions in
 swapin and improvements in performance are shown.
 
 "mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
 Improvements to the new unaccepted memory feature,
 
 "mm/mprotect: Fix dax puds" from Peter Xu.  Implements mprotect on DAX
 PUDs.  This was missing, although nobody seems to have notied yet.
 
 "Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
 Cleanups and modest performance improvements for the maple tree library
 code.
 
 "memcg: further decouple v1 code from v2" from Shakeel Butt.  Move more
 cgroup v1 remnants away from the v2 memcg code.
 
 "memcg: initiate deprecation of v1 features" from Shakeel Butt.  Adds
 various warnings telling users that memcg v1 features are deprecated.
 
 "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
 Greatly improves the success rate of the mTHP swap allocation.
 
 "mm: introduce numa_memblks" from Mike Rapoport.  Moves various disparate
 per-arch implementations of numa_memblk code into generic code.
 
 "mm: batch free swaps for zap_pte_range()" from Barry Song.  Greatly
 improves the performance of munmap() of swap-filled ptes.
 
 "support large folio swap-out and swap-in for shmem" from Baolin Wang.
 With this series we no longer split shmem large folios into simgle-page
 folios when swapping out shmem.
 
 "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao.  Nice performance
 improvements and code reductions for gigantic folios.
 
 "support shmem mTHP collapse" from Baolin Wang.  Adds support for
 khugepaged's collapsing of shmem mTHP folios.
 
 "mm: Optimize mseal checks" from Pedro Falcato.  Fixes an mprotect()
 performance regression due to the addition of mseal().
 
 "Increase the number of bits available in page_type" from Matthew Wilcox.
 Increases the number of bits available in page_type!
 
 "Simplify the page flags a little" from Matthew Wilcox.  Many legacy page
 flags are now folio flags, so the page-based flags and their
 accessors/mutators can be removed.
 
 "mm: store zero pages to be swapped out in a bitmap" from Usama Arif.  An
 optimization which permits us to avoid writing/reading zero-filled zswap
 pages to backing store.
 
 "Avoid MAP_FIXED gap exposure" from Liam Howlett.  Fixes a race window
 which occurs when a MAP_FIXED operqtion is occurring during an unrelated
 vma tree walk.
 
 "mm: remove vma_merge()" from Lorenzo Stoakes.  Major rotorooting of the
 vma_merge() functionality, making ot cleaner, more testable and better
 tested.
 
 "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.  Minor
 fixups of DAMON selftests and kunit tests.
 
 "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.  Code
 cleanups and folio conversions.
 
 "Shmem mTHP controls and stats improvements" from Ryan Roberts.  Cleanups
 for shmem controls and stats.
 
 "mm: count the number of anonymous THPs per size" from Barry Song.  Expose
 additional anon THP stats to userspace for improved tuning.
 
 "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
 conversions and removal of now-unused page-based APIs.
 
 "replace per-quota region priorities histogram buffer with per-context
 one" from SeongJae Park.  DAMON histogram rationalization.
 
 "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
 Park.  DAMON documentation updates.
 
 "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
 related doc and warn" from Jason Wang: fixes usage of page allocator
 __GFP_NOFAIL and GFP_ATOMIC flags.
 
 "mm: split underused THPs" from Yu Zhao.  Improve THP=always policy - this
 was overprovisioning THPs in sparsely accessed memory areas.
 
 "zram: introduce custom comp backends API" frm Sergey Senozhatsky.  Add
 support for zram run-time compression algorithm tuning.
 
 "mm: Care about shadow stack guard gap when getting an unmapped area" from
 Mark Brown.  Fix up the various arch_get_unmapped_area() implementations
 to better respect guard areas.
 
 "Improve mem_cgroup_iter()" from Kinsey Ho.  Improve the reliability of
 mem_cgroup_iter() and various code cleanups.
 
 "mm: Support huge pfnmaps" from Peter Xu.  Extends the usage of huge
 pfnmap support.
 
 "resource: Fix region_intersects() vs add_memory_driver_managed()" from
 Huang Ying.  Fix a bug in region_intersects() for systems with CXL memory.
 
 "mm: hwpoison: two more poison recovery" from Kefeng Wang.  Teaches a
 couple more code paths to correctly recover from the encountering of
 poisoned memry.
 
 "mm: enable large folios swap-in support" from Barry Song.  Support the
 swapin of mTHP memory into appropriately-sized folios, rather than into
 single-page folios.
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Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
 2024-09-21 07:29:05 -07:00
Peter Xu
ae3c99e650 mm/gup: detect huge pfnmap entries in gup-fast 
Since gup-fast doesn't have the vma reference, teach it to detect such huge
pfnmaps by checking the special bit for pmd/pud too, just like ptes.

Link: https://lkml.kernel.org/r/20240826204353.2228736-6-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-17 01:06:58 -07:00
Kundan Kumar
d3bfbfb124 mm: release number of pages of a folio 
Add a new function unpin_user_folio() to put the refs of a folio by
npages count.

The check for BIO_PAGE_PINNED flag is removed as it is already checked
in bio_release_pages().

Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240911064935.5630-4-kundan.kumar@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 2024-09-11 07:24:01 -06:00
Kefeng Wang
5c8525a37b mm: migrate_device: convert to migrate_device_coherent_folio() 
Patch series "mm: finish isolate/putback_lru_page()".

Convert to use more folios in migrate_device.c, then we could remove
isolate_lru_page() and putback_lru_page().  


This patch (of 6):

Save a few calls to compound_head() and use folio throughout.

Link: https://lkml.kernel.org/r/20240826065814.1336616-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240826065814.1336616-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-09 16:38:58 -07:00
David Hildenbrand
7290840de6 mm: remove follow_page() 
All users are gone, let's remove it and any leftovers in comments.  We'll
leave any FOLL/follow_page_() naming cleanups as future work.

Link: https://lkml.kernel.org/r/20240802155524.517137-11-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-01 20:26:01 -07:00
David Hildenbrand
b967c64890 mm/gup: convert to arch_make_folio_accessible() 
Let's use arch_make_folio_accessible() instead so we can get rid of
arch_make_page_accessible().

Link: https://lkml.kernel.org/r/20240729183844.388481-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-01 20:25:52 -07:00
Josef Bacik
dc21e70079 mm: remove foll_flags in __get_user_pages 
Now that we're not passing around a pointer to the flags, there's no
reason to have an extra variable for the gup_flags, simply pass the
gup_flags directly everywhere.

Link: https://lkml.kernel.org/r/1e79b84bd30287cc9847f2aeb002374e6e60a10f.1721337845.git.josef@toxicpanda.com
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-01 20:25:46 -07:00
Josef Bacik
478729533e mm: cleanup flags usage in faultin_page 
Patch series "mm: some small page fault cleanups".

I was recently wreaking havoc in the page fault code and I noticed some
things that could be cleaned up.  We no longer modify the gup flags in
faultin_page, so we can clean up how we pass the flags in and remove the
extra variable in __get_user_pages.


This patch (of 2):

We're passing a pointer to the foll_flags for faultin_page, however we
never modify the flags in this call.  Change this to just take the flags
value instead.

Link: https://lkml.kernel.org/r/2df51a54c06bdf93e1cb09a19a9ef1df6557b59e.1721337845.git.josef@toxicpanda.com
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-09-01 20:25:46 -07:00
Christophe Leroy
8268614b40 mm: remove CONFIG_ARCH_HAS_HUGEPD 
powerpc was the only user of CONFIG_ARCH_HAS_HUGEPD and doesn't use it
anymore, so remove all related code.

Link: https://lkml.kernel.org/r/4b10c54c794780b955f3ad6c657d0199dd792146.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-07-12 15:52:19 -07:00
Christophe Leroy
e6c0c03245 mm: provide mm_struct and address to huge_ptep_get() 
On powerpc 8xx huge_ptep_get() will need to know whether the given ptep is
a PTE entry or a PMD entry.  This cannot be known with the PMD entry
itself because there is no easy way to know it from the content of the
entry.

So huge_ptep_get() will need to know either the size of the page or get
the pmd.

In order to be consistent with huge_ptep_get_and_clear(), give mm and
address to huge_ptep_get().

Link: https://lkml.kernel.org/r/cc00c70dd384298796a4e1b25d6c4eb306d3af85.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-07-12 15:52:15 -07:00
Vivek Kasireddy
89c1905d9c mm/gup: introduce memfd_pin_folios() for pinning memfd folios 
For drivers that would like to longterm-pin the folios associated with a
memfd, the memfd_pin_folios() API provides an option to not only pin the
folios via FOLL_PIN but also to check and migrate them if they reside in
movable zone or CMA block.  This API currently works with memfds but it
should work with any files that belong to either shmemfs or hugetlbfs. 
Files belonging to other filesystems are rejected for now.

The folios need to be located first before pinning them via FOLL_PIN.  If
they are found in the page cache, they can be immediately pinned. 
Otherwise, they need to be allocated using the filesystem specific APIs
and then pinned.

[akpm@linux-foundation.org: improve the CONFIG_MMU=n situation, per SeongJae]
[vivek.kasireddy@intel.com: return -EINVAL if the end offset is greater than the size of memfd]
  Link: https://lkml.kernel.org/r/IA0PR11MB71850525CBC7D541CAB45DF1F8DB2@IA0PR11MB7185.namprd11.prod.outlook.com
Link: https://lkml.kernel.org/r/20240624063952.1572359-4-vivek.kasireddy@intel.com
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> (v2)
Reviewed-by: David Hildenbrand <david@redhat.com> (v3)
Reviewed-by: Christoph Hellwig <hch@lst.de> (v6)
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Junxiao Chang <junxiao.chang@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-07-12 15:52:09 -07:00
Vivek Kasireddy
53ba78de06 mm/gup: introduce check_and_migrate_movable_folios() 
This helper is the folio equivalent of check_and_migrate_movable_pages(). 
Therefore, all the rules that apply to check_and_migrate_movable_pages()
also apply to this one as well.  Currently, this helper is only used by
memfd_pin_folios().

This patch also includes changes to rename and convert the internal
functions collect_longterm_unpinnable_pages() and
migrate_longterm_unpinnable_pages() to work on folios.  As a result,
check_and_migrate_movable_pages() is now a wrapper around
check_and_migrate_movable_folios().

Link: https://lkml.kernel.org/r/20240624063952.1572359-3-vivek.kasireddy@intel.com
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Junxiao Chang <junxiao.chang@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-07-12 15:52:09 -07:00