From 96645678cd726e87ce42a0664de71e047e32bca4 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 19 Jul 2007 01:49:00 -0700 Subject: 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 Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/lockdep.h | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 3d3386b88b6..0e843bf6587 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 */ -- cgit v1.2.3