linux/arch
Takuya Yoshikawa 914ebccd2d KVM: x86: avoid unnecessary bitmap allocation when memslot is clean
Although we always allocate a new dirty bitmap in x86's get_dirty_log(),
it is only used as a zero-source of copy_to_user() and freed right after
that when memslot is clean. This patch uses clear_user() instead of doing
this unnecessary zero-source allocation.

Performance improvement: as we can expect easily, the time needed to
allocate a bitmap is completely reduced. In my test, the improved ioctl
was about 4 to 10 times faster than the original one for clean slots.
Furthermore, reducing memory allocations and copies will produce good
effects to caches too.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:27 +03:00
..
alpha alpha: Detect Super IO chip, no IDE on Avanti, enable EPP19 2010-06-15 14:19:08 -04:00
arm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6 2010-07-28 19:59:55 -07:00
avr32 serial: fix rs485 for atmel_serial on avr32 2010-07-26 11:59:31 -07:00
blackfin blackfin: use use asm-generic/scatterlist.h 2010-05-27 09:12:55 -07:00
cris Merge branch 'for-linus' of git://www.jni.nu/cris 2010-06-01 08:51:25 -07:00
frv FRV: Reinstate null behaviour for the GDB remote protocol 'p' command 2010-06-09 12:42:44 -07:00
h8300 Merge branch 'for-35' of git://repo.or.cz/linux-kbuild 2010-06-01 08:55:52 -07:00
ia64 [IA64] Fix spinaphore down_spin() 2010-06-30 10:46:16 -07:00
m32r m32r: invoke oom-killer from page fault 2010-06-04 15:21:44 -07:00
m68k Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k 2010-05-27 10:19:19 -07:00
m68knommu Merge branch 'for-35' of git://repo.or.cz/linux-kbuild 2010-06-01 08:55:52 -07:00
microblaze lmb: rename to memblock 2010-07-14 17:14:00 +10:00
mips MIPS: Set io_map_base for several PCI bridges lacking it 2010-07-26 19:08:19 +01:00
mn10300 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2010-06-11 14:15:44 -07:00
parisc Merge branch 'for-35' of git://repo.or.cz/linux-kbuild 2010-06-01 08:55:52 -07:00
powerpc perf, powerpc: Use perf_sample_data_init() for the FSL code 2010-07-27 22:20:09 +10:00
s390 [S390] Update default configuration. 2010-06-08 18:58:23 +02:00
score asm-generic: remove ISA_DMA_THRESHOLD in scatterlist.h 2010-05-27 09:12:54 -07:00
sh lmb: rename to memblock 2010-07-14 17:14:00 +10:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6 2010-07-21 09:28:50 -07:00
um um: os-linux/mem.c needs sys/stat.h 2010-06-29 15:29:32 -07:00
x86 KVM: x86: avoid unnecessary bitmap allocation when memslot is clean 2010-08-01 10:35:27 +03:00
xtensa xtensa: invoke oom-killer from page fault 2010-06-04 15:21:44 -07:00
.gitignore
Kconfig