Re: pre6 VM issues

From: Marcelo Tosatti (
Date: Tue Oct 09 2001 - 08:23:24 EST

On Tue, 9 Oct 2001, Andrea Arcangeli wrote:

> On Tue, Oct 09, 2001 at 10:44:37AM -0200, Marcelo Tosatti wrote:
> >
> > Hi,
> >
> > I've been testing pre6 (actually its pre5 a patch which Linus sent me
> > named "prewith 16GB of RAM (thanks to OSDLabs for that), and I've found
> > out some problems. First of all, we need to throttle normal allocators
> > more often and/or update the low memory limits for normal allocators to a
> > saner value. I already said I think allowing everybody to eat up to
> > "freepages.min" is too low for a default.
> >
> > I've got atomic memory failures with _22GB_ of swap free (32GB total):
> >
> > eth0: can't fill rx buffer (force 0)!
> >
> > Another issue is the damn fork() special case. Its failing in practice:
> >
> > bash: fork: Cannot allocate memory
> >
> > Also with _LOTS_ of swap free. (gigs of them)
> >
> > Linus, we can introduce a "__GFP_FAIL" flag to be used by _everyone_ which
> > wants to do higher order allocations as an optimization (eg allocate big
> > scatter-gather tables or whatever). Or do you prefer to make the fork()
> > allocation a separate case ?
> >
> > I'll take a closer look at the code now and make the throttling/limits to
> > what I think is saner for a default.
> I've also finished last night to fix all highmem troubles that I could
> reproduce on 128mbyte with highmem emulation, I'm confidetn it will work
> fine on real highmem too now, I hope to get access soon to some highmem
> machine too to test it.
> I guess you're not interested to test my patches since they're not in
> the mainline direction though.

Ah, I forgot something: Even if I'm not interested in the patches the 16GB
machine is available to the community. If you (or any other VM people who
need the machine) want access, just tell me.

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This archive was generated by hypermail 2b29 : Mon Oct 15 2001 - 21:00:25 EST