Messages in this thread | | | Date | Mon, 16 Mar 2009 12:11:22 +0000 | From | Mel Gorman <> | Subject | Re: [PATCH 00/35] Cleanup and optimise the page allocator V3 |
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On Mon, Mar 16, 2009 at 12:45:55PM +0100, Nick Piggin wrote: > On Mon, Mar 16, 2009 at 09:45:55AM +0000, Mel Gorman wrote: > > Here is V3 of an attempt to cleanup and optimise the page allocator and should > > be ready for general testing. The page allocator is now faster (16% > > reduced time overall for kernbench on one machine) and it has a smaller cache > > footprint (16.5% less L1 cache misses and 19.5% less L2 cache misses for > > kernbench on one machine). The text footprint has unfortunately increased, > > largely due to the introduction of a form of lazy buddy merging mechanism > > that avoids cache misses by postponing buddy merging until a high-order > > allocation needs it. > > BTW. I would feel better about this if it gets merged in stages, with > functional changes split out, and also code optimisations and omore > obvious performace improvements split out and preferably merged first. >
The ordering of the patches was such that least-controversial stuff is at the start of the patchset. The intention was to be able to select a cut-off point and say "that's enough for now"
> At a very quick glance, the first 25 or so patches should go in first, > and that gives a much better base to compare subsequent functional > changes with.
That's reasonable. I've requeued tests for the patchset up to 25 to see what that looks like. There is also a part of a later patch that reduces how much time is spent with interrupts disabled. I should split that out and move it back to within the cut-off point as something that is "obviously good".
> Patch 18 for example is really significant, and should > almost be 2.6.29/-stable material IMO. >
My impression was that -stable was only for functional regressions where as this is really a performance thing.
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab
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