Re: Where is the performance bottleneck?

From: Al Boldi
Date: Tue Aug 30 2005 - 23:32:09 EST


Holger Kiehl wrote:
> On Mon, 29 Aug 2005, Al Boldi wrote:
> > You may be hitting a 2.6 kernel bug, which has something to do with
> > readahead, ask Jens Axboe about it! (see "[git patches] IDE update"
> > thread) Sadly, 2.6.13 did not fix it either.
>
> I did read that threat, but due to my limited understanding about kernel
> code, don't see the relation to my problem.

Basically the kernel is loosing CPU cycles while accessing bockdevices.
The problem shows most when the CPU/DISK ratio is low.
Throwing more CPU cycles at the problem may seemingly remove this bottleneck.

> But I am willing to try any patches to solve the problem.

No patches yet.

> > Did you try 2.4.31?
>
> No. Will give this a try if the problem is not found.

Keep us posted!

--
Al
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