linux/arch
Michael Ellerman 3405d230b3 powerpc: Add support for the optimised lockref implementation
This commit adds the architecture support required to enable the
optimised implementation of lockrefs.

That's as simple as defining arch_spin_value_unlocked() and selecting
the Kconfig option.

We also define cmpxchg64_relaxed(), because the lockref code does not
need the cmpxchg to have barrier semantics.

Using Linus' test case[1] on one system I see a 4x improvement for the
basic enablement, and a further 1.3x for cmpxchg64_relaxed(), for a
total of 5.3x vs the baseline.

On another system I see more like 2x improvement.

[1]: http://marc.info/?l=linux-fsdevel&m=137782380714721&w=4

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-28 14:45:43 +11:00
..
alpha Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha 2013-11-20 15:03:45 -08:00
arc Final set of ARC changes for 3.13-rc1 2013-11-19 11:44:15 -08:00
arm Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm 2013-11-22 09:56:51 -08:00
arm64 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
avr32 avr32: uapi: be sure of "_UAPI" prefix for all guard macros 2013-11-20 09:53:22 +01:00
blackfin Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
c6x Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
cris Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
frv Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
hexagon Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
ia64 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-20 14:25:39 -08:00
m32r Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
m68k Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
metag Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
microblaze Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
mips Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
mn10300 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
openrisc OpenRISC updates for 3.13 2013-11-15 14:26:38 -08:00
parisc parisc: size_t is unsigned, so comparison size < 0 doesn't make sense. 2013-11-20 00:09:42 +01:00
powerpc powerpc: Add support for the optimised lockref implementation 2014-01-28 14:45:43 +11:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2013-11-19 11:43:21 -08:00
score Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
sh Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2013-11-19 15:50:03 -08:00
tile Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2013-11-19 11:42:32 -08:00
unicore32 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
x86 Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux 2013-11-22 10:56:11 -08:00
xtensa Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
.gitignore
Kconfig kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS 2013-11-15 09:32:22 +09:00