From: Vivek Goyal <vgoyal@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>,
avi@redhat.com, nate@cpanel.net, cl@linux-foundation.org,
oleg@redhat.com, axboe@kernel.dk, linux-kernel@vger.kernel.org
Subject: Re: [PATCHSET] block, mempool, percpu: implement percpu mempool and fix blkcg percpu alloc deadlock
Date: Fri, 23 Dec 2011 09:46:47 -0500 [thread overview]
Message-ID: <20111223144647.GA16818@redhat.com> (raw)
In-Reply-To: <20111222175834.66559c8b.akpm@linux-foundation.org>
On Thu, Dec 22, 2011 at 05:58:34PM -0800, Andrew Morton wrote:
> On Thu, 22 Dec 2011 20:40:43 -0500 Vivek Goyal <vgoyal@redhat.com> wrote:
>
> > That's why the need of per cpu data structures to make stat collection
> > lockless.
>
> btw, (and this is a common refrain): was there any reason for avoiding
> using percpu_counters here?
IIUC, per cpu counters also call alloc_percpu() during initialization.
int __percpu_counter_init(struct percpu_counter *fbc, s64 amount,
struct lock_class_key *key)
{
raw_spin_lock_init(&fbc->lock);
lockdep_set_class(&fbc->lock, key);
fbc->count = amount;
fbc->counters = alloc_percpu(s32);
....
....
}
So they are no good either for allocation and initialization in IO path.
Thanks
Vivek
prev parent reply other threads:[~2011-12-23 14:47 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-22 21:45 [PATCHSET] block, mempool, percpu: implement percpu mempool and fix blkcg percpu alloc deadlock Tejun Heo
2011-12-22 21:45 ` [PATCH 1/7] mempool: fix and document synchronization and memory barrier usage Tejun Heo
2011-12-22 21:45 ` [PATCH 2/7] mempool: drop unnecessary and incorrect BUG_ON() from mempool_destroy() Tejun Heo
2011-12-22 21:45 ` [PATCH 3/7] mempool: fix first round failure behavior Tejun Heo
2011-12-22 21:45 ` [PATCH 4/7] mempool: factor out mempool_fill() Tejun Heo
2011-12-22 21:45 ` [PATCH 5/7] mempool: separate out __mempool_create() Tejun Heo
2011-12-22 21:45 ` [PATCH 6/7] mempool, percpu: implement percpu mempool Tejun Heo
2011-12-22 21:45 ` [PATCH 7/7] block: fix deadlock through percpu allocation in blk-cgroup Tejun Heo
2011-12-23 1:00 ` Vivek Goyal
2011-12-23 22:54 ` Tejun Heo
2011-12-22 21:59 ` [PATCHSET] block, mempool, percpu: implement percpu mempool and fix blkcg percpu alloc deadlock Andrew Morton
2011-12-22 22:09 ` Tejun Heo
2011-12-22 22:20 ` Andrew Morton
2011-12-22 22:41 ` Tejun Heo
2011-12-22 22:54 ` Andrew Morton
2011-12-22 23:00 ` Tejun Heo
2011-12-22 23:16 ` Andrew Morton
2011-12-22 23:24 ` Tejun Heo
2011-12-22 23:41 ` Andrew Morton
2011-12-22 23:54 ` Tejun Heo
2011-12-23 1:14 ` Andrew Morton
2011-12-23 15:17 ` Vivek Goyal
2011-12-27 18:34 ` Tejun Heo
2011-12-27 21:20 ` Andrew Morton
2011-12-27 21:44 ` Tejun Heo
2011-12-27 21:58 ` Andrew Morton
2011-12-27 22:22 ` Tejun Heo
2011-12-23 1:21 ` Vivek Goyal
2011-12-23 1:38 ` Andrew Morton
2011-12-23 2:54 ` Vivek Goyal
2011-12-23 3:11 ` Andrew Morton
2011-12-23 14:58 ` Vivek Goyal
2011-12-27 21:25 ` Andrew Morton
2011-12-27 22:07 ` Tejun Heo
2011-12-27 22:21 ` Andrew Morton
2011-12-27 22:30 ` Tejun Heo
2012-01-16 15:26 ` Vivek Goyal
2011-12-23 1:40 ` Vivek Goyal
2011-12-23 1:58 ` Andrew Morton
2011-12-23 2:56 ` Vivek Goyal
2011-12-26 6:05 ` KAMEZAWA Hiroyuki
2011-12-27 17:52 ` Tejun Heo
2011-12-28 0:14 ` KAMEZAWA Hiroyuki
2011-12-28 0:41 ` Tejun Heo
2012-01-05 1:28 ` Tejun Heo
2012-01-16 15:28 ` Vivek Goyal
2012-02-09 23:58 ` Tejun Heo
2012-02-10 16:26 ` Vivek Goyal
2012-02-13 22:31 ` Tejun Heo
2012-02-15 15:43 ` Vivek Goyal
2011-12-23 14:46 ` Vivek Goyal [this message]
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