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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2007-07-19 01:49:00 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-19 10:04:49 -0700
commit96645678cd726e87ce42a0664de71e047e32bca4 (patch)
tree116f568a090414777b481e8e5d9db55f420e4335 /include
parent443aef0eddfa44c158d1b94ebb431a70638fcab4 (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.h17
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 */