x86-64: remove locked instruction from switch_to()
authorBenjamin LaHaise <bcrl@kvack.org>
Sun, 11 Jan 2009 04:00:22 +0000 (23:00 -0500)
committerIngo Molnar <mingo@elte.hu>
Sun, 11 Jan 2009 04:05:33 +0000 (05:05 +0100)
commit7106a5ab89c50c6b5aadea0850b40323804a922d
treed4ce5df5ff89da035b6dd092bbe089757def7c34
parentc59765042f53a79a7a65585042ff463b69cb248c
x86-64: remove locked instruction from switch_to()

Impact: micro-optimization

The patch below removes an unnecessary locked instruction from
switch_to().  TIF_FORK is only ever set in copy_thread() on initial
process creation, and gets cleared during the first scheduling of the
process.  As such, it is safe to use an unlocked test for the flag
within switch_to().

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/include/asm/system.h
arch/x86/kernel/entry_64.S