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 /kernel/lockdep_proc.c | |
| parent | 443aef0eddfa44c158d1b94ebb431a70638fcab4 (diff) | |
| download | lwn-96645678cd726e87ce42a0664de71e047e32bca4.tar.gz lwn-96645678cd726e87ce42a0664de71e047e32bca4.zip | |
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 'kernel/lockdep_proc.c')
| -rw-r--r-- | kernel/lockdep_proc.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index 39163ed1bf0a..7ff80135cbeb 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c @@ -430,16 +430,18 @@ static void seq_stats(struct seq_file *m, struct lock_stat_data *data) else seq_printf(m, "%40s:", name); + seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]); seq_lock_time(m, &stats->write_waittime); - seq_puts(m, " "); + seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]); seq_lock_time(m, &stats->write_holdtime); seq_puts(m, "\n"); } if (stats->read_holdtime.nr) { seq_printf(m, "%38s-R:", name); + seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]); seq_lock_time(m, &stats->read_waittime); - seq_puts(m, " "); + seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]); seq_lock_time(m, &stats->read_holdtime); seq_puts(m, "\n"); } @@ -469,26 +471,29 @@ static void seq_stats(struct seq_file *m, struct lock_stat_data *data) } if (i) { seq_puts(m, "\n"); - seq_line(m, '.', 0, 40 + 1 + 8 * (14 + 1)); + seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1)); seq_puts(m, "\n"); } } static void seq_header(struct seq_file *m) { - seq_printf(m, "lock_stat version 0.1\n"); - seq_line(m, '-', 0, 40 + 1 + 8 * (14 + 1)); - seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s\n", + seq_printf(m, "lock_stat version 0.2\n"); + seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1)); + seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s " + "%14s %14s\n", "class name", + "con-bounces", "contentions", "waittime-min", "waittime-max", "waittime-total", + "acq-bounces", "acquisitions", "holdtime-min", "holdtime-max", "holdtime-total"); - seq_line(m, '-', 0, 40 + 1 + 8 * (14 + 1)); + seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1)); seq_printf(m, "\n"); } |