Home
last modified time | relevance | path

Searched hist:"2 d4d57db" (Results 1 – 1 of 1) sorted by relevance

/openbmc/linux/arch/x86/include/asm/
H A Dspinlock.h2d4d57db Sun Jan 25 14:50:13 CST 2009 Frederic Weisbecker <fweisbec@gmail.com> 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>
2d4d57db Sun Jan 25 14:50:13 CST 2009 Frederic Weisbecker <fweisbec@gmail.com> 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>