From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id A34D66B0011 for ; Wed, 11 May 2011 16:59:05 -0400 (EDT) Received: from hpaq5.eem.corp.google.com (hpaq5.eem.corp.google.com [172.25.149.5]) by smtp-out.google.com with ESMTP id p4BKx2bw011615 for ; Wed, 11 May 2011 13:59:02 -0700 Received: from pwi8 (pwi8.prod.google.com [10.241.219.8]) by hpaq5.eem.corp.google.com with ESMTP id p4BKwHSj005378 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Wed, 11 May 2011 13:59:01 -0700 Received: by pwi8 with SMTP id 8so495553pwi.8 for ; Wed, 11 May 2011 13:59:00 -0700 (PDT) Date: Wed, 11 May 2011 13:58:59 -0700 (PDT) From: David Rientjes Subject: Re: slub: Add statistics for this_cmpxchg_double failures In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Pekka Enberg , linux-mm@kvack.org 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 --- 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: email@kvack.org