linux/arch
Chris Wilson 1f1a89ac05 x86/mm: Micro-optimise clflush_cache_range()
Whilst inspecting the asm for clflush_cache_range() and some perf profiles
that required extensive flushing of single cachelines (from part of the
intel-gpu-tools GPU benchmarks), we noticed that gcc was reloading
boot_cpu_data.x86_clflush_size on every iteration of the loop. We can
manually hoist that read which perf regarded as taking ~25% of the
function time for a single cacheline flush.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com>
Link: http://lkml.kernel.org/r/1452246933-10890-1-git-send-email-chris@chris-wilson.co.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-08 19:27:39 +01:00
..
alpha
arc ARC fixes for 4.4-rc1 2015-11-14 09:09:37 -08:00
arm USB fixes for 4.4-rc2 2015-11-22 13:15:05 -08:00
arm64 arm64 fixes: 2015-11-19 12:21:23 -08:00
avr32 dmaengine updates for 4.4-rc1 2015-11-10 10:05:17 -08:00
blackfin
c6x
cris
frv
h8300 h8300 update for v4.4 2015-11-12 15:26:39 -08:00
hexagon
ia64
m32r
m68k
metag Metag architecture changes for v4.4 2015-11-10 16:24:25 -08:00
microblaze
mips MIPS: ath79: Add a machine entry for booting OF machines 2015-11-20 15:44:57 +01:00
mn10300
nios2
openrisc
parisc Merge branch 'parisc-4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2015-11-22 12:50:58 -08:00
powerpc powerpc: Wire up sys_mlock2() 2015-11-16 17:05:53 +11:00
s390 s390: remove SALIPL loader 2015-11-16 12:51:11 +01:00
score
sh
sparc
tile
um
unicore32 pwm: Changes for v4.4-rc1 2015-11-11 09:16:10 -08:00
x86 x86/mm: Micro-optimise clflush_cache_range() 2016-01-08 19:27:39 +01:00
xtensa Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-block 2015-11-10 17:23:49 -08:00
.gitignore
Kconfig