From: Tejun Heo <tj@kernel.org>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>,
Andrew Morton <akpm@linux-foundation.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: Tue, 27 Dec 2011 09:52:49 -0800 [thread overview]
Message-ID: <20111227175249.GE17712@google.com> (raw)
In-Reply-To: <20111226150531.3c22f2f0.kamezawa.hiroyu@jp.fujitsu.com>
Hello, KAMEZAWA.
On Mon, Dec 26, 2011 at 03:05:31PM +0900, KAMEZAWA Hiroyuki wrote:
> From 433b56fd5644d4b1e695bc16bbf8dd78842999fd Mon Sep 17 00:00:00 2001
> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Date: Mon, 26 Dec 2011 15:06:21 +0900
> Subject: [PATCH] percpu_counter: add lazy init
>
> percpu_counter calls alloc_percpu(). This means percpu_counter_init()
> assumes GFP_KERNEL context. This may call vmalloc() in percpu_counter
> allocation and will have locks.
>
> If a caller doesn't want to assume GFP_KERNEL, we need some tricks.
> This patch adds percpu_counter_init_lazy().
>
> At lazy allocation, the function leaves fbc->counters as NULL and
> init fbc->counters by workqueue. This work item handling is done
> by fbc->list, so, the struct size of 'fbc' will not increase if
> a user configs CONFIG_HOTPLUG_CPU.
This is essentially more specialized form of the mempool approach. It
doesn't seem any simpler to me while being less generic. I don't see
what the upside would be.
Thanks.
--
tejun
next prev parent reply other threads:[~2011-12-27 17:52 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 [this message]
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
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