2009-11-19 21:42:09

by Frank Rowand

Subject: [PATCH] LOCKSTAT: patch test - Fix min, max times in /proc/lock_stats

Fix min, max times in /proc/lock_stats

(1) When collecting lock hold and wait times, if the current minimum time is
zero, it will be replaced by the next time.

(2) When aggregating minimum and maximum lock hold and wait times accross cpus,
the values are added, instead of selecting the minimum and maximum.


Signed-off-by: Frank Rowand <[email protected]>

---
kernel/lockdep.c | 11 9 + 2 - 0 !
1 files changed, 9 insertions(+), 2 deletions(-)

Index: linux-2.6/kernel/lockdep.c
===================================================================
--- linux-2.6.orig/kernel/lockdep.c
+++ linux-2.6/kernel/lockdep.c
@@ -168,7 +168,7 @@ static void lock_time_inc(struct lock_ti
if (time > lt->max)
lt->max = time;

- if (time < lt->min || !lt->min)
+ if (time < lt->min || !lt->nr)
lt->min = time;

lt->total += time;
@@ -177,8 +177,15 @@ static void lock_time_inc(struct lock_ti

static inline void lock_time_add(struct lock_time *src, struct lock_time *dst)
{
- dst->min += src->min;
- dst->max += src->max;
+ if (!src->nr)
+ return;
+
+ if (src->max > dst->max)
+ dst->max = src->max;
+
+ if (src->min < dst->min || !dst->nr)
+ dst->min = src->min;
+
dst->total += src->total;
dst->nr += src->nr;
}

2009-11-19 22:29:55

by Peter Zijlstra

Subject: Re: [PATCH] LOCKSTAT: patch test - Fix min, max times in /proc/lock_stats

On Thu, 2009-11-19 at 13:42 -0800, Frank Rowand wrote:
> Fix min, max times in /proc/lock_stats
>
> (1) When collecting lock hold and wait times, if the current minimum time is
> zero, it will be replaced by the next time.
>
> (2) When aggregating minimum and maximum lock hold and wait times accross cpus,
> the values are added, instead of selecting the minimum and maximum.
>
>
> Signed-off-by: Frank Rowand <[email protected]>

Thanks Frank, took both patches.

2009-12-06 13:04:18

by Frank Rowand

Subject: [tip:core/urgent] lockstat: Fix min, max times in /proc/lock_stats

Commit-ID: 109d71c6dd52ec08878c2c67eb4c0bd67fcbc80b
Gitweb: http://git.kernel.org/tip/109d71c6dd52ec08878c2c67eb4c0bd67fcbc80b
Author: Frank Rowand <[email protected]>
AuthorDate: Thu, 19 Nov 2009 13:42:06 -0800
Committer: Ingo Molnar <[email protected]>
CommitDate: Sun, 6 Dec 2009 13:20:00 +0100

lockstat: Fix min, max times in /proc/lock_stats

Fix min, max times in /proc/lock_stats

(1) When collecting lock hold and wait times, if the current minimum
time is zero, it will be replaced by the next time.

(2) When aggregating minimum and maximum lock hold and wait times
accross cpus, the values are added, instead of selecting the
minimum and maximum.

Signed-off-by: Frank Rowand <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
---
kernel/lockdep.c | 13 ++++++++++---
1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f5dcd36..7a3ae56 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -168,7 +168,7 @@ static void lock_time_inc(struct lock_time *lt, u64 time)
if (time > lt->max)
lt->max = time;

- if (time < lt->min || !lt->min)
+ if (time < lt->min || !lt->nr)
lt->min = time;

lt->total += time;
@@ -177,8 +177,15 @@ static void lock_time_inc(struct lock_time *lt, u64 time)

static inline void lock_time_add(struct lock_time *src, struct lock_time *dst)
{
- dst->min += src->min;
- dst->max += src->max;
+ if (!src->nr)
+ return;
+
+ if (src->max > dst->max)
+ dst->max = src->max;
+
+ if (src->min < dst->min || !dst->nr)
+ dst->min = src->min;
+
dst->total += src->total;
dst->nr += src->nr;
}