From: Vivek Goyal <vgoyal@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: axboe@kernel.dk, ctalbott@google.com, rni@google.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/12] blkcg: use the usual get blkg path for root blkio_group
Date: Thu, 19 Jan 2012 09:41:36 -0500 [thread overview]
Message-ID: <20120119144136.GB9582@redhat.com> (raw)
In-Reply-To: <1326935490-11827-9-git-send-email-tj@kernel.org>
On Wed, Jan 18, 2012 at 05:11:26PM -0800, Tejun Heo wrote:
> For root blkg, blk_throtl_init() was using throtl_alloc_tg()
> explicitly and cfq_init_queue() was manually initializing embedded
> cfqd->root_group, adding unnecessarily different code paths to blkg
> handling.
>
> Make both use the usual blkio_group get functions - throtl_get_tg()
> and cfq_get_cfqg() - for the root blkio_group too. Note that
> blk_throtl_init() callsite is pushed downwards in
> blk_alloc_queue_node() so that @q is sufficiently initialized for
> throtl_get_tg().
>
> This simplifies root blkg handling noticeably for cfq and will allow
> further modularization of blkcg API.
Does this work if BLK_CGROUP=n?
I am trying to think that why did I keep allocating root cgroup statically
for CFQ. May be the reason was that this group was present even if
CFQ_GROUP_IOSCHED=n. There was other code which assumed a group to be
always present and I did not want to put more #ifdef.
Anyway, if it works well, with BLK_CGROUP=n, then it is fine.
Thanks
Vivek
next prev parent reply other threads:[~2012-01-19 14:41 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-19 1:11 [PATCHSET] blkcg: kill policy node and blkg->dev Tejun Heo
2012-01-19 1:11 ` [PATCH 01/12] blkcg: obtaining blkg should be enclosed inside rcu_read_lock() Tejun Heo
2012-01-19 10:07 ` Vivek Goyal
2012-01-19 15:39 ` Tejun Heo
2012-01-19 15:54 ` Vivek Goyal
2012-01-19 15:58 ` Tejun Heo
2012-01-19 1:11 ` [PATCH 02/12] cfq: don't register propio policy if !CONFIG_CFQ_GROUP_IOSCHED Tejun Heo
2012-01-19 10:11 ` Vivek Goyal
2012-01-19 1:11 ` [PATCH 03/12] elevator: clear auxiliary data earlier during elevator switch Tejun Heo
2012-01-19 1:11 ` [PATCH 04/12] elevator: make elevator_init_fn() return 0/-errno Tejun Heo
2012-01-19 11:11 ` Vivek Goyal
2012-01-19 15:44 ` Tejun Heo
2012-01-19 1:11 ` [PATCH 05/12] blkcg: update blkg get functions take blkio_cgroup as parameter Tejun Heo
2012-01-19 11:21 ` Vivek Goyal
2012-01-19 15:45 ` Tejun Heo
2012-01-19 1:11 ` [PATCH 06/12] blkcg: use q and plid instead of opaque void * for blkio_group association Tejun Heo
2012-01-19 14:04 ` Vivek Goyal
2012-01-19 15:55 ` Tejun Heo
2012-01-19 16:16 ` Vivek Goyal
2012-01-19 16:25 ` Tejun Heo
2012-01-19 16:42 ` Tejun Heo
2012-01-19 1:11 ` [PATCH 07/12] blkcg: add blkio_policy[] array and allow one policy per policy ID Tejun Heo
2012-01-19 1:11 ` [PATCH 08/12] blkcg: use the usual get blkg path for root blkio_group Tejun Heo
2012-01-19 14:41 ` Vivek Goyal [this message]
2012-01-19 16:17 ` Tejun Heo
2012-01-19 1:11 ` [PATCH 09/12] blkcg: factor out blkio_group creation Tejun Heo
2012-01-19 1:11 ` [PATCH 10/12] blkcg: don't allow or retain configuration of missing devices Tejun Heo
2012-01-19 1:11 ` [PATCH 11/12] blkcg: kill blkio_policy_node Tejun Heo
2012-01-19 20:32 ` Vivek Goyal
2012-01-19 22:03 ` Tejun Heo
2012-01-19 22:30 ` Vivek Goyal
2012-01-19 1:11 ` [PATCH 12/12] blkcg: kill the mind-bending blkg->dev Tejun Heo
2012-01-19 15:49 ` Vivek Goyal
2012-01-19 16:30 ` Tejun Heo
2012-01-19 16:46 ` Vivek Goyal
2012-01-19 1:18 ` [PATCHSET] blkcg: kill policy node and blkg->dev Tejun Heo
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