Re: [RFC PATCH] block: Fix bio merge induced high I/O latency

[Leon Woestenberg]

Hello Mathieu et al,

On Sat, Jan 17, 2009 at 5:26 PM, Mathieu Desnoyers
<mathieu.desnoyers@xxxxxxxxxx> wrote:
> A long standing I/O regression (since 2.6.18, still there today) has hit
> Slashdot recently :
> http://bugzilla.kernel.org/show_bug.cgi?id=12309

Are you sure you are solving the *actual* problem?

The bugzilla entry shows a bisect attempt that leads to a patch
involving negative clock jumps.
http://bugzilla.kernel.org/show_bug.cgi?id=12309#c29

with a corrected link to the bisect patch:
http://bugzilla.kernel.org/show_bug.cgi?id=12309#c30

Wouldn't a negative clock jump be very influential to the
(time-driven) I/O schedulers and be a more probable cause?

Regards,
-- 
Leon

p.s. Added Thomas to the CC list as his name is on the patch Signed-off-by list.
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