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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-01-25 12:50:13 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-26 14:06:36 +0100 |
| commit | 2d4d57db692ea790e185656516e6ebe8791f1788 (patch) | |
| tree | f7ad21dbcb4d5de2f0eb63024c1b5f1bf5321d76 /arch/x86/kernel/trampoline_64.S | |
| parent | 7106a5ab89c50c6b5aadea0850b40323804a922d (diff) | |
| download | blackbird-op-linux-2d4d57db692ea790e185656516e6ebe8791f1788.tar.gz blackbird-op-linux-2d4d57db692ea790e185656516e6ebe8791f1788.zip | |
x86: micro-optimize __raw_read_trylock()
The current version of __raw_read_trylock starts with decrementing the lock
and read its new value as a separate operation after that.
That makes 3 dereferences (read, write (after sub), read) whereas
a single atomic_dec_return does only two pointers dereferences (read, write).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/trampoline_64.S')
0 files changed, 0 insertions, 0 deletions
