Re: 2.4.1 under heavy network load - more info

[Rik van Riel]

On Fri, 23 Feb 2001, Chris Evans wrote:
> On Wed, 21 Feb 2001, Rik van Riel wrote:
>
> > I'm really interested in things which make Linux 2.4 break
> > performance-wise since I'd like to have them fixed before the
> > distributions start shipping 2.4 as default.
>
> With kernel 2.4.1, I found that caching is way too aggressive. I
> was running konqueror in 32Mb (the quest for a lightwieght
> browser!) Unfortunately, the system seemed to insist on keeping
> 16Mb used for caches, with 15Mb given to the application and X.

Wrong.

Cache and processes are INCLUSIVE. Konquerer and your other
applications will share a lot of memory with the cache. More
precisely, everything which is backed by a file or has been
swapped out once (and swapped back in later) will SHARE memory
with both cache and processes.

In 2.4.1-pre<something> the kernel swaps out cache 32 times more
agressively than it scans pages in processes. Until we find a way
to auto-balance these things, expect them to be wrong for at least
some workloads ;(

regards,

Rik
--
Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...

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