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wuqiang.matt 4bbd934556 kprobes: kretprobe scalability improvement
kretprobe is using freelist to manage return-instances, but freelist,
as LIFO queue based on singly linked list, scales badly and reduces
the overall throughput of kretprobed routines, especially for high
contention scenarios.

Here's a typical throughput test of sys_prctl (counts in 10 seconds,
measured with perf stat -a -I 10000 -e syscalls:sys_enter_prctl):

OS: Debian 10 X86_64, Linux 6.5rc7 with freelist
HW: XEON 8336C x 2, 64 cores/128 threads, DDR4 3200MT/s

         1T       2T       4T       8T      16T      24T
   24150045 29317964 15446741 12494489 18287272 17708768
        32T      48T      64T      72T      96T     128T
   16200682 13737658 11645677 11269858 10470118  9931051

This patch introduces objpool to replace freelist. objpool is a
high performance queue, which can bring near-linear scalability
to kretprobed routines. Tests of kretprobe throughput show the
biggest ratio as 159x of original freelist. Here's the result:

                  1T         2T         4T         8T        16T
native:     41186213   82336866  164250978  328662645  658810299
freelist:   24150045   29317964   15446741   12494489   18287272
objpool:    23926730   48010314   96125218  191782984  385091769
                 32T        48T        64T        96T       128T
native:   1330338351 1969957941 2512291791 2615754135 2671040914
freelist:   16200682   13737658   11645677   10470118    9931051
objpool:   764481096 1147149781 1456220214 1502109662 1579015050

Testings on 96-core ARM64 output similarly, but with the biggest
ratio up to 448x:

OS: Debian 10 AARCH64, Linux 6.5rc7
HW: Kunpeng-920 96 cores/2 sockets/4 NUMA nodes, DDR4 2933 MT/s

                  1T         2T         4T         8T        16T
native: .   30066096   63569843  126194076  257447289  505800181
freelist:   16152090   11064397   11124068    7215768    5663013
objpool:    13997541   28032100   55726624  110099926  221498787
                 24T        32T        48T        64T        96T
native:    763305277 1015925192 1521075123 2033009392 3021013752
freelist:    5015810    4602893    3766792    3382478    2945292
objpool:   328192025  439439564  668534502  887401381 1319972072

Link: https://lore.kernel.org/all/20231017135654.82270-4-wuqiang.matt@bytedance.com/

Signed-off-by: wuqiang.matt <wuqiang.matt@bytedance.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-18 23:59:54 +09:00
arch Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
block block: fix kernel-doc for disk_force_media_change() 2023-09-26 00:43:34 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: sm2 - Fix crash caused by uninitialized context 2023-09-20 13:10:10 +08:00
Documentation Kbuild fixes for v6.6 (2nd) 2023-10-01 13:48:46 -07:00
drivers Misc driver fix for 6.6-rc4 2023-10-01 12:50:04 -07:00
fs Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
include kprobes: kretprobe scalability improvement 2023-10-18 23:59:54 +09:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io_uring/fs: remove sqe->rw_flags checking from LINKAT 2023-09-29 03:07:09 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel kprobes: kretprobe scalability improvement 2023-10-18 23:59:54 +09:00
lib lib: objpool test module added 2023-10-18 22:36:03 +09:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
net Networking fixes for 6.6-rc2, including fixes from netfilter and bpf 2023-09-21 11:28:16 -07:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples samples: kprobes: Fixes a typo 2023-10-10 01:00:50 +09:00
scripts kbuild: remove stale code for 'source' symlink in packaging scripts 2023-10-01 23:06:06 +09:00
security selinux: fix handling of empty opts in selinux_fs_context_submount() 2023-09-12 17:31:08 -04:00
sound ASoC: Fixes for v6.6 2023-09-20 15:02:16 +02:00
tools Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap for-linus-2023083101 2023-09-01 12:31:44 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS ARM: SoC fixes for 6.6 2023-09-30 18:41:37 -07:00
Makefile Linux 6.6-rc4 2023-10-01 14:15:13 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.