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e35735b9a5
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Anton Blanchard e35735b9a5 powerpc: Speed up clear_page by unrolling it 
Unroll clear_page 8 times. A simple microbenchmark which
allocates and frees a zeroed page:

for (i = 0; i < iterations; i++) {
	unsigned long p = __get_free_page(GFP_KERNEL | __GFP_ZERO);
	free_page(p);
}

improves 20% on POWER8.

This assumes cacheline sizes won't grow beyond 512 bytes or
page sizes wont drop below 1kB, which is unlikely, but we could
add a runtime check during early init if it makes people nervous.

Michael found that some versions of gcc produce quite bad code
(all multiplies), so we give gcc a hand by using shifts and adds.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-02 16:04:21 +10:00
..
alpha alpha: io: implement relaxed accessor macros for writes 2014-08-29 11:18:45 -07:00
arc ARC: [mm] Fix compilation breakage 2014-09-03 10:08:50 -07:00
arm Fix "xen_add_mach_to_phys_entry: cannot add" problem on xen on arm and 2014-09-12 17:45:27 -07:00
arm64 arm64 fixes for -rc5 2014-09-12 09:53:47 -07:00
avr32 Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
blackfin Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
c6x Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
cris Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
frv frv: Define cpu_relax_lowlatency() 2014-08-19 09:40:08 -05:00
hexagon flush_icache_range: export symbol to fix build errors 2014-08-29 16:28:17 -07:00
ia64 kexec: remove CONFIG_KEXEC dependency on crypto 2014-08-29 16:28:16 -07:00
m32r Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
m68k m68k: Wire up memfd_create 2014-09-01 10:28:00 +02:00
metag Metag architecture changes for v3.17 2014-08-13 18:18:09 -06:00
microblaze microblaze: Fix number of syscalls 2014-09-09 13:14:47 +02:00
mips kexec: remove CONFIG_KEXEC dependency on crypto 2014-08-29 16:28:16 -07:00
mn10300 Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
openrisc Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
parisc parisc: Implement new LWS CAS supporting 64 bit operations. 2014-09-13 22:40:48 +02:00
powerpc powerpc: Speed up clear_page by unrolling it 2014-10-02 16:04:21 +10:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-09-08 08:27:00 -07:00
score Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
sh sh: get_user_pages_fast() must flush cache 2014-09-10 15:42:12 -07:00
sparc sparc: Hook up memfd_create system call. 2014-08-13 22:00:09 -07:00
tile flush_icache_range: export symbol to fix build errors 2014-08-29 16:28:17 -07:00
um Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
unicore32 unicore32: Fix build error 2014-08-31 17:08:12 -07:00
x86 Make ARCH_HAS_FAST_MULTIPLIER a real config variable 2014-09-13 11:14:53 -07:00
xtensa Xtensa improvements for 3.17: 2014-08-31 17:08:42 -07:00
.gitignore
Kconfig seccomp: add "seccomp" syscall 2014-07-18 12:13:37 -07:00