Re: -mm merge plans for 2.6.23

From: david
Date: Wed Jul 25 2007 - 04:35:41 EST


On Wed, 25 Jul 2007, david@xxxxxxx wrote:

Subject: Re: -mm merge plans for 2.6.23

On Wed, 25 Jul 2007, Rene Herman wrote:

On 07/25/2007 10:07 AM, david@xxxxxxx wrote:

> On Wed, 25 Jul 2007, Rene Herman wrote:

> > Something like this?

[ ... ]

> when the swap readahead is enabled does it make a significant > difference
> in the time to do the random access?

I don't use swap prefetch (nor -ck or -mm). If someone who has the patch
applied waits to hit enter until swap prefetch has prefetched it all back
in again, it certainly will.

Swap prefetch's potential to do larger reads back from swapspace than a
random segfaulting app could well be very significant. Reads are dwarved
by seeks. If this program does what you wanted, please use it to show us.

I haven't used swap prefetch either, the call was put out for what could be used to test the performance, and I was suggesting a test.

if nobody else follows up on this I'll try to get some time to test it myself in a day or two.

this assumes that this isn't ruled an invalid test in the meantime.

in any case thanks for codeing this up so quickly.

David Lang
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