Re: [PATCH 0/5] make slab gfp fair

Peter Zijlstra
2007-05-16T06:59:44Z

On Tue, 2007-05-15 at 15:02 -0700, Christoph Lameter wrote:
> On Tue, 15 May 2007, Peter Zijlstra wrote:
>
> > How about something like this; it seems to sustain a little stress.
>
> Argh again mods to kmem_cache.

Hmm, I had not understood you minded that very much; I did stay away
from all the fast paths this time.

The thing is, I wanted to fold all the emergency allocs into a single
slab, not a per cpu thing. And once you loose the per cpu thing, you
need some extra serialization. Currently the top level lock is
slab_lock(page), but that only works because we have interrupts disabled
and work per cpu.

Why is it bad to extend kmem_cache a bit?