Re: [PATCH 2/3] Fix fsync livelock

From: Pavel Machek
Date: Wed Oct 08 2008 - 12:46:34 EST


On Sun 2008-10-05 17:30:19, Arjan van de Ven wrote:
> On Sun, 5 Oct 2008 20:01:46 -0400 (EDT)
> Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote:
>
> > I assume that if very few people complained about the livelock till
> > now, very few people will see degraded write performance. My patch
> > blocks the writes only if the livelock happens, so if the livelock
> > doesn't happen in unpatched kernel for most people, the patch won't
> > make it worse.
>
> I object to calling this a livelock. It's not.

8 hours of process in D state is a livelock. And we can do minimal fix
here, this almost never happens in real life anyway.

Latency imposed of writer should not be a problem...
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