All of lore.kernel.org
 help / color / mirror / Atom feed
* slub: Add statistics for this_cmpxchg_double failures
@ 2011-03-22 18:35 Christoph Lameter
  2011-05-11 20:58 ` David Rientjes
  0 siblings, 1 reply; 6+ messages in thread
From: Christoph Lameter @ 2011-03-22 18:35 UTC (permalink / raw)
  To: Pekka Enberg; +Cc: linux-mm

Add some statistics for debugging.

Signed-off-by: Christoph Lameter <cl@linux.com>

---
 include/linux/slub_def.h |    1 +
 mm/slub.c                |    3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6/include/linux/slub_def.h
===================================================================
--- linux-2.6.orig/include/linux/slub_def.h	2011-03-11 10:34:26.000000000 -0600
+++ linux-2.6/include/linux/slub_def.h	2011-03-11 10:34:49.000000000 -0600
@@ -32,6 +32,7 @@ enum stat_item {
 	DEACTIVATE_TO_TAIL,	/* Cpu slab was moved to the tail of partials */
 	DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
 	ORDER_FALLBACK,		/* Number of times fallback was necessary */
+	CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
 	NR_SLUB_STAT_ITEMS };

 struct kmem_cache_cpu {
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-03-11 10:34:27.000000000 -0600
+++ linux-2.6/mm/slub.c	2011-03-11 10:34:49.000000000 -0600
@@ -217,7 +217,7 @@ static inline void sysfs_slab_remove(str

 #endif

-static inline void stat(struct kmem_cache *s, enum stat_item si)
+static inline void stat(const struct kmem_cache *s, enum stat_item si)
 {
 #ifdef CONFIG_SLUB_STATS
 	__this_cpu_inc(s->cpu_slab->stat[si]);
@@ -1551,6 +1551,7 @@ static inline void note_cmpxchg_failure(
 		printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
 			actual_tid, tid, next_tid(tid));
 #endif
+	stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
 }

 #endif

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: slub: Add statistics for this_cmpxchg_double failures
  2011-03-22 18:35 slub: Add statistics for this_cmpxchg_double failures Christoph Lameter
@ 2011-05-11 20:58 ` David Rientjes
  2011-05-12 14:44   ` Christoph Lameter
  0 siblings, 1 reply; 6+ messages in thread
From: David Rientjes @ 2011-05-11 20:58 UTC (permalink / raw)
  To: Christoph Lameter; +Cc: Pekka Enberg, linux-mm

On Tue, 22 Mar 2011, Christoph Lameter wrote:

> Index: linux-2.6/include/linux/slub_def.h
> ===================================================================
> --- linux-2.6.orig/include/linux/slub_def.h	2011-03-11 10:34:26.000000000 -0600
> +++ linux-2.6/include/linux/slub_def.h	2011-03-11 10:34:49.000000000 -0600
> @@ -32,6 +32,7 @@ enum stat_item {
>  	DEACTIVATE_TO_TAIL,	/* Cpu slab was moved to the tail of partials */
>  	DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
>  	ORDER_FALLBACK,		/* Number of times fallback was necessary */
> +	CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
>  	NR_SLUB_STAT_ITEMS };
> 
>  struct kmem_cache_cpu {
> Index: linux-2.6/mm/slub.c
> ===================================================================
> --- linux-2.6.orig/mm/slub.c	2011-03-11 10:34:27.000000000 -0600
> +++ linux-2.6/mm/slub.c	2011-03-11 10:34:49.000000000 -0600
> @@ -217,7 +217,7 @@ static inline void sysfs_slab_remove(str
> 
>  #endif
> 
> -static inline void stat(struct kmem_cache *s, enum stat_item si)
> +static inline void stat(const struct kmem_cache *s, enum stat_item si)
>  {
>  #ifdef CONFIG_SLUB_STATS
>  	__this_cpu_inc(s->cpu_slab->stat[si]);
> @@ -1551,6 +1551,7 @@ static inline void note_cmpxchg_failure(
>  		printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
>  			actual_tid, tid, next_tid(tid));
>  #endif
> +	stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
>  }
> 
>  #endif

I see this has been merged as 4fdccdfbb465, but it seems pretty pointless 
unless you export the data to userspace with the necessary STAT_ATTR() and 
addition in slab_attrs.


slub: export CMPXCHG_DOUBLE_CPU_FAIL to userspace

4fdccdfbb465 ("slub: Add statistics for this_cmpxchg_double failures") 
added CMPXCHG_DOUBLE_CPU_FAIL to show how many times 
this_cpu_cmpxchg_double has failed, but it also needs to be exported to 
userspace for consumption.

This will always be 0 if CONFIG_CMPXCHG_LOCAL is disabled.

Signed-off-by: David Rientjes <rientjes@google.com>
---
 mm/slub.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4525,6 +4525,7 @@ STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
 STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
 STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
 STAT_ATTR(ORDER_FALLBACK, order_fallback);
+STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
 #endif
 
 static struct attribute *slab_attrs[] = {
@@ -4582,6 +4583,7 @@ static struct attribute *slab_attrs[] = {
 	&deactivate_to_tail_attr.attr,
 	&deactivate_remote_frees_attr.attr,
 	&order_fallback_attr.attr,
+	&cmpxchg_double_cpu_fail_attr.attr,
 #endif
 #ifdef CONFIG_FAILSLAB
 	&failslab_attr.attr,

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: slub: Add statistics for this_cmpxchg_double failures
  2011-05-11 20:58 ` David Rientjes
@ 2011-05-12 14:44   ` Christoph Lameter
  2011-05-12 19:58     ` David Rientjes
  0 siblings, 1 reply; 6+ messages in thread
From: Christoph Lameter @ 2011-05-12 14:44 UTC (permalink / raw)
  To: David Rientjes; +Cc: Pekka Enberg, linux-mm

On Wed, 11 May 2011, David Rientjes wrote:

> I see this has been merged as 4fdccdfbb465, but it seems pretty pointless
> unless you export the data to userspace with the necessary STAT_ATTR() and
> addition in slab_attrs.

Right that slipped into a later patch that only dealt with statistics. But
I will fold that into the earlier patch.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: slub: Add statistics for this_cmpxchg_double failures
  2011-05-12 14:44   ` Christoph Lameter
@ 2011-05-12 19:58     ` David Rientjes
  2011-05-13 14:48       ` Christoph Lameter
  0 siblings, 1 reply; 6+ messages in thread
From: David Rientjes @ 2011-05-12 19:58 UTC (permalink / raw)
  To: Christoph Lameter; +Cc: Pekka Enberg, linux-mm

On Thu, 12 May 2011, Christoph Lameter wrote:

> > I see this has been merged as 4fdccdfbb465, but it seems pretty pointless
> > unless you export the data to userspace with the necessary STAT_ATTR() and
> > addition in slab_attrs.
> 
> Right that slipped into a later patch that only dealt with statistics. But
> I will fold that into the earlier patch.
> 

I think since CMPXCHG_DOUBLE_CPU_FAIL is already merged as 4fdccdfbb465 
that my patch should be merged to export it?

Not sure what patch you intend to fold this into.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: slub: Add statistics for this_cmpxchg_double failures
  2011-05-12 19:58     ` David Rientjes
@ 2011-05-13 14:48       ` Christoph Lameter
  2011-05-24  9:40         ` [patch] slub: export CMPXCHG_DOUBLE_CPU_FAIL to userspace David Rientjes
  0 siblings, 1 reply; 6+ messages in thread
From: Christoph Lameter @ 2011-05-13 14:48 UTC (permalink / raw)
  To: David Rientjes; +Cc: Pekka Enberg, linux-mm

On Thu, 12 May 2011, David Rientjes wrote:

> On Thu, 12 May 2011, Christoph Lameter wrote:
>
> > > I see this has been merged as 4fdccdfbb465, but it seems pretty pointless
> > > unless you export the data to userspace with the necessary STAT_ATTR() and
> > > addition in slab_attrs.
> >
> > Right that slipped into a later patch that only dealt with statistics. But
> > I will fold that into the earlier patch.
> >
>
> I think since CMPXCHG_DOUBLE_CPU_FAIL is already merged as 4fdccdfbb465
> that my patch should be merged to export it?

Sure. I have no objections.

Acked-by: Christoph Lameter <cl@linux.com>

> Not sure what patch you intend to fold this into.

Into the statistics patch for the lockless slowpaths.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [patch] slub: export CMPXCHG_DOUBLE_CPU_FAIL to userspace
  2011-05-13 14:48       ` Christoph Lameter
@ 2011-05-24  9:40         ` David Rientjes
  0 siblings, 0 replies; 6+ messages in thread
From: David Rientjes @ 2011-05-24  9:40 UTC (permalink / raw)
  To: Pekka Enberg; +Cc: Christoph Lameter, linux-mm

4fdccdfbb465 ("slub: Add statistics for this_cmpxchg_double failures") 
added CMPXCHG_DOUBLE_CPU_FAIL to show how many times 
this_cpu_cmpxchg_double has failed, but it also needs to be exported to 
userspace for consumption.

This will always be 0 if CONFIG_CMPXCHG_LOCAL is disabled.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: David Rientjes <rientjes@google.com>
---
 mm/slub.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4525,6 +4525,7 @@ STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
 STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
 STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
 STAT_ATTR(ORDER_FALLBACK, order_fallback);
+STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
 #endif
 
 static struct attribute *slab_attrs[] = {
@@ -4582,6 +4583,7 @@ static struct attribute *slab_attrs[] = {
 	&deactivate_to_tail_attr.attr,
 	&deactivate_remote_frees_attr.attr,
 	&order_fallback_attr.attr,
+	&cmpxchg_double_cpu_fail_attr.attr,
 #endif
 #ifdef CONFIG_FAILSLAB
 	&failslab_attr.attr,

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-05-24  9:40 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-03-22 18:35 slub: Add statistics for this_cmpxchg_double failures Christoph Lameter
2011-05-11 20:58 ` David Rientjes
2011-05-12 14:44   ` Christoph Lameter
2011-05-12 19:58     ` David Rientjes
2011-05-13 14:48       ` Christoph Lameter
2011-05-24  9:40         ` [patch] slub: export CMPXCHG_DOUBLE_CPU_FAIL to userspace David Rientjes

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.