Date: Thu, 26 Nov 2009 09:14:09 +0100
From: Jens Axboe <jens.axboe@oracle.com>
To: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Cc: czoccolo@gmail.com, Vivek Goyal <vgoyal@redhat.com>,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cfq: Make use of service count to estimate the rb_key
	offset
Message-ID: <20091126081409.GL8742@kernel.dk>
References: <4B0E1E2F.9080604@cn.fujitsu.com>
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On Thu, Nov 26 2009, Gui Jianfeng wrote:
> Hi Jens, Czoccolo
> 
> For the moment, different workload cfq queues are put into different
> service trees. But CFQ still uses "busy_queues" to estimate rb_key 
> offset when inserting a cfq queue into a service tree. I think this 
> isn't appropriate, and it should make use of service tree count to do 
> this estimation. This patch is for for-2.6.33 branch.

Makes sense, we've before discussed that using ->busy_queues isn't very
good, as it's not a stable count. service_tree count isn't that much
better, but for for-2.6.33 it does make more sense.

-- 
Jens Axboe

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