Re: 2.2.19pre6aa1 degraded performance for me...

Sasi Peter (sape@iq.rulez.org)
Tue, 9 Jan 2001 07:25:27 +0100 (CET)


On Tue, 9 Jan 2001, Andrea Arcangeli wrote:

> On Mon, Jan 08, 2001 at 10:46:29PM +0100, Sasi Peter wrote:
> > What I had w/2.2.18pre19 (+raid+ide):
> > ~80MB more in cache and ~80MB swapped out (eg. currently unused notes
> > server and squid) There is enough of swap over 3 disks (like the
> > raid), so I did not bother disabling squid and notes, since - I thought -
> > they would only take up some swap unused.
>
> There are many variables. However I guess the slowdown is because your idle
> apps didn't got swapped out in favour of cache as you noticed. An aggressive
> aging algorithm would probably fix that but it then would hurt other cases
> (after you don't need a frequenty accessed part of filesystem cache anymore it
> would take ages before it gets collected potentially causing an unnecessary
> swapout storms because the kernel doesn't know you don't need such cache
> anymore). Furthmore if notes and squid are rarely running but they provides
> critical services if they would go totally into swap in favour of fs cache you
> would get very bad latencies the first time somebody connects to the server. So
> the fix I suggest you is to buy more ram or to shutdown squid and notes. Than

Oh well I thought 384MB should be enought for everyone aiming at this
performance (almost TM ;). At least it would up till now :(

> you may as well see a performance improvement compared to 2.2.18pre19
> (+raid+ide). Otherwise you can push the machine low on memory a bit until they
> both goes totally into swap (check with `ps v`). Hope this helps.

I'll try this, thanks. (so no echo '1 23 456' >/proc/sys/vm/...?)

-- 
SaPE - Peter, Sasi - mailto:sape@sch.hu - http://sape.iq.rulez.org/

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