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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2007-07-19 01:49:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-19 10:04:49 -0700 |
| commit | 96645678cd726e87ce42a0664de71e047e32bca4 (patch) | |
| tree | 116f568a090414777b481e8e5d9db55f420e4335 /Documentation/early-userspace | |
| parent | 443aef0eddfa44c158d1b94ebb431a70638fcab4 (diff) | |
lockstat: measure lock bouncing
__acquire
|
lock _____
| \
| __contended
| |
| wait
| _______/
|/
|
__acquired
|
__release
|
unlock
We measure acquisition and contention bouncing.
This is done by recording a cpu stamp in each lock instance.
Contention bouncing requires the cpu stamp to be set on acquisition. Hence we
move __acquired into the generic path.
__acquired is then used to measure acquisition bouncing by comparing the
current cpu with the old stamp before replacing it.
__contended is used to measure contention bouncing (only useful for preemptable
locks)
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/early-userspace')
0 files changed, 0 insertions, 0 deletions