linux-toradex.git/include/asm-generic/mutex-dec.h, branch v3.4.99 Linux kernel for Apalis and Colibri modules mutex: speed up generic mutex implementations 2008-10-23T16:18:20+00:00 Nick Piggin npiggin@suse.de 2008-10-21T08:59:15+00:00 a8ddac7e53e89cb877965097d05adfeb1c91def3 - atomic operations which both modify the variable and return something imply full smp memory barriers before and after the memory operations involved (failing atomic_cmpxchg, atomic_add_unless, etc don't imply a barrier because they don't modify the target). See Documentation/atomic_ops.txt. So remove extra barriers and branches. - All architectures support atomic_cmpxchg. This has no relation to __HAVE_ARCH_CMPXCHG. We can just take the atomic_cmpxchg path unconditionally This reduces a simple single threaded fastpath lock+unlock test from 590 cycles to 203 cycles on a ppc970 system. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
- atomic operations which both modify the variable and return something imply
  full smp memory barriers before and after the memory operations involved
  (failing atomic_cmpxchg, atomic_add_unless, etc don't imply a barrier because
  they don't modify the target). See Documentation/atomic_ops.txt.
  So remove extra barriers and branches.

- All architectures support atomic_cmpxchg. This has no relation to
  __HAVE_ARCH_CMPXCHG. We can just take the atomic_cmpxchg path unconditionally

This reduces a simple single threaded fastpath lock+unlock test from 590 cycles
to 203 cycles on a ppc970 system.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
asm-generic: remove fastcall 2008-02-08T17:22:31+00:00 Harvey Harrison harvey.harrison@gmail.com 2008-02-08T12:19:56+00:00 144b2a91468bdc0d4fa64b220c152fb58b8ffe05 Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fix file specification in comments 2006-10-03T21:01:26+00:00 Uwe Zeisberger Uwe_Zeisberger@digi.com 2006-10-03T21:01:26+00:00 f30c2269544bffc7bf1b0d7c0abe5be1be83b8cb Many files include the filename at the beginning, serveral used a wrong one. Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> 
Many files include the filename at the beginning, serveral used a wrong one.

Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
[PATCH] mutex: some cleanups 2006-03-31T20:19:01+00:00 Nicolas Pitre nico@cam.org 2006-03-31T10:32:13+00:00 e358c1a2c45f7ec32d77cc09a2bb42d6823a4193 Turn some macros into inline functions and add proper type checking as well as being more readable. Also a minor comment adjustment. Signed-off-by: Nicolas Pitre <nico@cam.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> 
Turn some macros into inline functions and add proper type checking as
well as being more readable.  Also a minor comment adjustment.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix mutex_trylock() copy-and-paste bug (x86, x86-64, generic mutex-dec.h) 2006-01-11T23:50:47+00:00 Linus Torvalds torvalds@g5.osdl.org 2006-01-11T23:50:47+00:00 4cec87361462d570d6a67888feda41e77e0a9562 Noticed by Arjan originally on x86-64, then Ingo on x86, and finally me grepping for it in the generic version. Bad parenthesis nesting. Signed-off-by: Linus Torvalds <torvalds@osdl.org> 
Noticed by Arjan originally on x86-64, then Ingo on x86, and finally me
grepping for it in the generic version.

Bad parenthesis nesting.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] mutex subsystem, add asm-generic/mutex-[dec|xchg|null].h implementations 2006-01-09T23:59:17+00:00 Ingo Molnar mingo@elte.hu 2006-01-09T23:59:17+00:00 620a6fd185c084aa617c411f711533f01ea673c9 Add three (generic) mutex fastpath implementations. The mutex-xchg.h implementation is atomic_xchg() based, and should work fine on every architecture. The mutex-dec.h implementation is atomic_dec_return() based - this one too should work on every architecture, but might not perform the most optimally on architectures that have no atomic-dec/inc instructions. The mutex-null.h implementation forces all calls into the slowpath. This is used for mutex debugging, but it can also be used on platforms that do not want (or need) a fastpath at all. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> 
Add three (generic) mutex fastpath implementations.

The mutex-xchg.h implementation is atomic_xchg() based, and should
work fine on every architecture.

The mutex-dec.h implementation is atomic_dec_return() based - this
one too should work on every architecture, but might not perform the
most optimally on architectures that have no atomic-dec/inc instructions.

The mutex-null.h implementation forces all calls into the slowpath. This
is used for mutex debugging, but it can also be used on platforms that do
not want (or need) a fastpath at all.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>