Re: Linux 2.4.4-ac10

[Mike Galbraith]

On Fri, 18 May 2001, Stephen C. Tweedie wrote:

> Hi,
>
> On Fri, May 18, 2001 at 07:44:39PM -0300, Rik van Riel wrote:
>
> > This is the core of why we cannot (IMHO) have a discussion
> > of whether a patch introducing new VM tunables can go in:
> > there is no clear overview of exactly what would need to be
> > tunable and how it would help.
>
> It's worse than that.  The workload on most typical systems is not
> static.  The VM *must* be able to cope with dynamic workloads.  You
> might twiddle all the knobs on your system to make your database run
> faster, but end up in such a situation that the next time a mail flood
> arrives for sendmail, the whole box locks up because the VM can no
> longer adapt.
>
> That's the main problem with static parameters.  The problem you are
> trying to solve is fundamentally dynamic in most cases (which is also
> why magic numbers tend to suck in the VM.)

Yup.  The problems are dynamic even with my static test load.

Off the top of my head, if I could make a suggestion to the vm it
would be something like "don't let dirty pages lay idle any longer
than this" and maybe "reclaim cleaned pages older than that".

	-Mike