From: Vladimir Davydov <vdavydov@parallels.com>
To: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: akpm@linux-foundation.org, cl@linux.com, rientjes@google.com,
penberg@kernel.org, hannes@cmpxchg.org, mhocko@suse.cz,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH -mm v2 5/8] slub: make slab_free non-preemptable
Date: Thu, 12 Jun 2014 14:03:46 +0400 [thread overview]
Message-ID: <20140612100344.GB19221@esperanza> (raw)
In-Reply-To: <20140612065842.GE19918@js1304-P5Q-DELUXE>
Hi,
On Thu, Jun 12, 2014 at 03:58:42PM +0900, Joonsoo Kim wrote:
> On Fri, Jun 06, 2014 at 05:22:42PM +0400, Vladimir Davydov wrote:
> > @@ -2673,18 +2673,11 @@ static __always_inline void slab_free(struct kmem_cache *s,
> >
> > slab_free_hook(s, x);
> >
> > -redo:
> > - /*
> > - * Determine the currently cpus per cpu slab.
> > - * The cpu may change afterward. However that does not matter since
> > - * data is retrieved via this pointer. If we are on the same cpu
> > - * during the cmpxchg then the free will succedd.
> > - */
> > preempt_disable();
>
> Could you add some code comment why this preempt_disable/enable() is
> needed? We don't have any clue that kmemcg depends on these things
> on code, so someone cannot understand why it is here.
>
> If possible, please add similar code comment on slab_alloc in mm/slab.c.
Sure.
Thanks.
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next prev parent reply other threads:[~2014-06-12 10:03 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-06 13:22 [PATCH -mm v2 0/8] memcg/slab: reintroduce dead cache self-destruction Vladimir Davydov
2014-06-06 13:22 ` [PATCH -mm v2 1/8] memcg: cleanup memcg_cache_params refcnt usage Vladimir Davydov
2014-06-06 13:22 ` [PATCH -mm v2 2/8] memcg: destroy kmem caches when last slab is freed Vladimir Davydov
2014-06-06 13:22 ` [PATCH -mm v2 3/8] memcg: mark caches that belong to offline memcgs as dead Vladimir Davydov
2014-06-10 7:48 ` Joonsoo Kim
2014-06-10 10:06 ` Vladimir Davydov
2014-06-06 13:22 ` [PATCH -mm v2 4/8] slub: don't fail kmem_cache_shrink if slab placement optimization fails Vladimir Davydov
2014-06-06 13:22 ` [PATCH -mm v2 5/8] slub: make slab_free non-preemptable Vladimir Davydov
2014-06-06 14:46 ` Christoph Lameter
2014-06-09 12:52 ` Vladimir Davydov
2014-06-09 13:52 ` Christoph Lameter
2014-06-12 6:58 ` Joonsoo Kim
2014-06-12 10:03 ` Vladimir Davydov [this message]
2014-06-06 13:22 ` [PATCH -mm v2 6/8] memcg: wait for kfree's to finish before destroying cache Vladimir Davydov
2014-06-06 13:22 ` [PATCH -mm v2 7/8] slub: make dead memcg caches discard free slabs immediately Vladimir Davydov
2014-06-06 14:48 ` Christoph Lameter
2014-06-10 8:09 ` Joonsoo Kim
2014-06-10 10:09 ` Vladimir Davydov
2014-06-06 13:22 ` [PATCH -mm v2 8/8] slab: " Vladimir Davydov
2014-06-06 14:52 ` Christoph Lameter
2014-06-09 13:04 ` Vladimir Davydov
2014-06-10 7:43 ` Joonsoo Kim
2014-06-10 10:03 ` Vladimir Davydov
2014-06-10 14:26 ` Christoph Lameter
2014-06-10 15:18 ` Vladimir Davydov
2014-06-11 8:11 ` Joonsoo Kim
2014-06-11 21:24 ` Vladimir Davydov
2014-06-12 6:53 ` Joonsoo Kim
2014-06-12 10:02 ` Vladimir Davydov
2014-06-13 16:34 ` Christoph Lameter
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