Re: updatedb

From: Jesper Juhl
Date: Thu Jul 26 2007 - 20:46:36 EST


On 26/07/07, Andika Triwidada <andika@xxxxxxxxx> wrote:
On 7/26/07, Rene Herman <rene.herman@xxxxxxxxx> wrote:
> On 07/25/2007 07:15 PM, Robert Deaton wrote:
>
> > On 7/25/07, Rene Herman <rene.herman@xxxxxxxxx> wrote:
>
> >> And there we go again -- off into blabber-land. Why does swap-prefetch
> >> help updatedb? Or doesn't it? And if it doesn't, why should anyone
> >> trust anything else someone who said it does says?
>
> > I don't think anyone has ever argued that swap-prefetch directly helps
> > the performance of updatedb in any way
>
> People have argued (claimed, rather) that swap-prefetch helps their system
> after updatedb has run -- you are doing so now.
>
> > however, I do recall people mentioning that updatedb, being a ram
> > intensive task, will often cause things to be swapped out while it runs
> > on say a nightly cronjob.
>
> Problem spot no. 1.
>
> RAM intensive? If I run updatedb here, it never grows itself beyond 2M. Yes,
> two. I'm certainly willing to accept that me and my systems are possibly not
> the reference but assuming I'm _very_ special hasn't done much for me either
> in the past.

Might be insignificant, but updatedb calls find (~2M) and sort (~26M).
Definitely not RAM intensive though (RAM is 1GB).


That doesn't match my box at all :

root@dragon:/home/juhl# free
total used free shared buffers cached
Mem: 2070856 1611548 459308 0 59312 740760
-/+ buffers/cache: 811476 1259380
Swap: 987988 0 987988

root@dragon:/home/juhl# updatedb

root@dragon:/home/juhl# free
total used free shared buffers cached
Mem: 2070856 1724204 346652 0 144708 745328
-/+ buffers/cache: 834168 1236688
Swap: 987988 0 987988


This is a Slackware Linux 12.0 system.


--
Jesper Juhl <jesper.juhl@xxxxxxxxx>
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