From: Tejun Heo <tj@kernel.org>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: axboe@kernel.dk, ctalbott@google.com, rni@google.com,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
containers@lists.linux-foundation.org
Subject: Re: [PATCH 07/11] blkcg: make request_queue bypassing on allocation
Date: Fri, 13 Apr 2012 13:47:10 -0700 [thread overview]
Message-ID: <20120413204710.GF12233@google.com> (raw)
In-Reply-To: <20120413204446.GK26383@redhat.com>
On Fri, Apr 13, 2012 at 04:44:46PM -0400, Vivek Goyal wrote:
> On Fri, Apr 13, 2012 at 01:37:26PM -0700, Tejun Heo wrote:
>
> [..]
> > blk_cleanup_queue() doesn't use blk_queue_bypass_start() to enter
> > bypass mode.
>
> Oh now elevator_exit() has been moved into blk_release_queue(). But
> problem will still be there, isn't it? During driver init, most likely driver
> is holding last reference of the queue and blk_release_queue() will be called
> in the context of blk_cleanup_queue() causing the overhead?
Hmmm? blk_cleanup_queue() will put the queue into bypassing mode
without going through synchronize_rcu() and all the following
bypassing operations just inc/decs bypass_depth without any draining
operation.
Thanks.
--
tejun
next prev parent reply other threads:[~2012-04-13 20:47 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-13 20:11 [PATCHSET] block: per-queue policy activation, take#2 Tejun Heo
2012-04-13 20:11 ` [PATCH 01/11] cfq: fix build breakage & warnings Tejun Heo
2012-04-13 20:11 ` [PATCH 02/11] blkcg: kill blkio_list and replace blkio_list_lock with a mutex Tejun Heo
2012-04-13 20:11 ` [PATCH 03/11] blkcg: use @pol instead of @plid in update_root_blkg_pd() and blkcg_print_blkgs() Tejun Heo
2012-04-13 20:11 ` [PATCH 04/11] blkcg: remove static policy ID enums Tejun Heo
2012-04-13 20:11 ` [PATCH 05/11] blkcg: make blkg_conf_prep() take @pol and return with queue lock held Tejun Heo
2012-04-13 20:11 ` [PATCH 06/11] blkcg: make sure blkg_lookup() returns %NULL if @q is bypassing Tejun Heo
2012-04-13 21:50 ` [PATCH UPDATED " Tejun Heo
2012-04-13 20:11 ` [PATCH 07/11] blkcg: make request_queue bypassing on allocation Tejun Heo
2012-04-13 20:32 ` Vivek Goyal
2012-04-13 20:37 ` Tejun Heo
2012-04-13 20:44 ` Vivek Goyal
2012-04-13 20:47 ` Tejun Heo [this message]
2012-04-13 20:55 ` Vivek Goyal
2012-04-13 21:05 ` Tejun Heo
2012-04-13 21:16 ` Tejun Heo
2012-04-13 21:31 ` Tejun Heo
2012-04-17 12:04 ` James Bottomley
2012-04-18 21:42 ` Tejun Heo
2012-04-13 21:33 ` Vivek Goyal
2012-04-13 21:38 ` Tejun Heo
2012-04-16 12:39 ` Vivek Goyal
2012-04-13 20:37 ` Vivek Goyal
2012-04-13 20:11 ` [PATCH 08/11] blkcg: add request_queue->root_blkg Tejun Heo
2012-04-13 20:11 ` [PATCH 09/11] blkcg: implement per-queue policy activation Tejun Heo
2012-04-13 20:11 ` [PATCH 10/11] blkcg: drop stuff unused after per-queue policy activation update Tejun Heo
2012-04-13 20:11 ` [PATCH 11/11] blkcg: shoot down blkgs if all policies are deactivated Tejun Heo
2012-04-20 8:09 ` [PATCHSET] block: per-queue policy activation, take#2 Jens Axboe
2012-04-20 12:02 ` Jens Axboe
2012-04-20 17:17 ` Tejun Heo
2012-04-20 19:08 ` Jens Axboe
2012-04-25 18:19 ` Tejun Heo
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