Messages in this thread | | | Date | Thu, 3 Apr 2008 10:32:31 +0200 | From | Nick Piggin <> | Subject | Re: [rfc] SLQB: YASA |
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On Thu, Apr 03, 2008 at 11:24:00AM +0300, Pekka Enberg wrote: > Hi Nick, > > On Thu, Apr 03, 2008 at 09:57:25AM +0200, Nick Piggin wrote: > > > It's a completely different design of the core allocator algorithms > > > really. > > > > > > It probably looks quite similar because I started with slub.c, but > > > really is just the peripheral supporting code and structure. I'm never > > > intending to try to go through the pain of incrementally changing SLUB > > > into SLQB. If SLQB is found to be a good idea, then it could maybe get > > > merged. > > On Thu, Apr 3, 2008 at 11:13 AM, Nick Piggin <npiggin@suse.de> wrote: > > And also I guess I don't think Christoph would be very happy about > > it :) He loves higher order allocations :) > > > > The high level choices are pretty clear and I simply think there might > > be a better way to do it. I'm not saying it *is* better because I simply > > don't know, and there are areas where the tradeoffs I've made means that > > in some situations SLQB cannot match SLUB. > > So do you disagree with Christoph's statement that we should fix page > allocator performance instead of adding queues to SLUB?
It's not just adding queues to SLUB, by any means (SLUB effectively already has queues anyway, with it's MIN_PARTIAL thing).
I think some page allocator performance can be improved (see my patch to remove the atomic refcounting for example). But in other cases the page allocator just has to do a lot more work and fixing it would just involve removing some of those things.
> I also don't > think higher order allocations are the answer for regular boxes but I > can see why they're useful for HPC people with huge machines.
I don't disagree with what you say. SLQB doesn't prevent them from being used.
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