diff options
| 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 /include | |
| 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 'include')
| -rw-r--r-- | include/linux/lockdep.h | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 3d3386b88b6a..0e843bf65877 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -130,12 +130,24 @@ struct lock_time { unsigned long nr; }; +enum bounce_type { + bounce_acquired_write, + bounce_acquired_read, + bounce_contended_write, + bounce_contended_read, + nr_bounce_types, + + bounce_acquired = bounce_acquired_write, + bounce_contended = bounce_contended_write, +}; + struct lock_class_stats { unsigned long contention_point[4]; struct lock_time read_waittime; struct lock_time write_waittime; struct lock_time read_holdtime; struct lock_time write_holdtime; + unsigned long bounces[nr_bounce_types]; }; struct lock_class_stats lock_stats(struct lock_class *class); @@ -150,6 +162,9 @@ struct lockdep_map { struct lock_class_key *key; struct lock_class *class_cache; const char *name; +#ifdef CONFIG_LOCK_STAT + int cpu; +#endif }; /* @@ -321,8 +336,8 @@ do { \ if (!try(_lock)) { \ lock_contended(&(_lock)->dep_map, _RET_IP_); \ lock(_lock); \ - lock_acquired(&(_lock)->dep_map); \ } \ + lock_acquired(&(_lock)->dep_map); \ } while (0) #else /* CONFIG_LOCK_STAT */ |