Re: pre6 VM issues

[Andrea Arcangeli]

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.

Andrea