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Message-ID: <3C63A10E.D5DF604A@zip.com.au>
Date: Fri, 08 Feb 2002 01:57:34 -0800
From: Andrew Morton <akpm@zip.com.au>
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To: Jens Axboe <axboe@suse.de>
CC: Rik van Riel <riel@conectiva.com.br>,
        William Lee Irwin III <wli@holomorphy.com>,
        lkml <linux-kernel@vger.kernel.org>
Subject: Re: [patch] get_request starvation fix
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		<3C639060.A68A42CA@zip.com.au> <20020208095739.J4942@suse.de>
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Jens Axboe wrote:
> 
> On Fri, Feb 08 2002, Andrew Morton wrote:
> > Here's a patch which addresses the get_request starvation problem.
> 
> [snip]
> 
> Agrh, if only I knew you were working on this too :/. Oh well, from a
> first-read the patch looks good.

Seems that with FIFO fairness, /bin/sync now also livelocks.  And
it's pretty easy to see why.  There's nothing to make
write_unlocked_buffers() terminate.

We'll worry about that tomorrow.  I may just make it give up
after writing (2 * nr_buffers_type[BUF_DIRTY]) buffers.

The patch works well with read-latency2 (and it didn't throw
rejects).  Smooth and fast.  It's going to take some time and
testing to settle everything in.


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