Date: Fri, 10 Jun 2011 05:17:47 -0400
From: Vivek Goyal <vgoyal@redhat.com>
To: Shaohua Li <shaohua.li@intel.com>
Cc: Tao Ma <tm@tao.ma>, linux-kernel@vger.kernel.org,
        Jens Axboe <axboe@kernel.dk>
Subject: Re: CFQ: async queue blocks the whole system
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On Fri, Jun 10, 2011 at 09:19:12AM +0800, Shaohua Li wrote:

[..]
> > If there is no major advantage of draining sync requests before async
> > is dispatched, I think this should be an easy fix.
> I thought this is to avoid sync latency if we switch from an async
> queue to sync queue later.

Is it about the sync request latency which has already been dispatched? I 
really wish that driver and disk should do some prioritazation for reads
here and CFQ does not have to jump through hoops like drain sync requests
before async requests are dispatched.

Thanks
Vivek
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