Messages in this thread | | | Date | Sat, 13 Aug 2011 11:28:30 -0700 (PDT) | From | David Rientjes <> | Subject | Re: [slub p4 0/7] slub: per cpu partial lists V4 |
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On Tue, 9 Aug 2011, Christoph Lameter wrote:
> The following patchset introduces per cpu partial lists which allow > a performance increase of around ~10-20% with hackbench on my Sandybridge > processor. > > These lists help to avoid per node locking overhead. Allocator latency > could be further reduced by making these operations work without > disabling interrupts (like the fastpath and the free slowpath) but that > is another project. > > It is interesting to note that BSD has gone to a scheme with partial > pages only per cpu (source: Adrian). Transfer of cpu ownerships is > done using IPIs. Probably too much overhead for our taste. The approach > here keeps the per node partial lists essentially meaning the "pages" > in there have no cpu owner. >
I'm currently 35,000 feet above Chicago going about 611 mph, so what better time to benchmark this patchset on my netperf testing rack!
threads before after 16 78031 74714 (-4.3%) 32 118269 115810 (-2.1%) 48 150787 150165 (-0.4%) 64 189932 187766 (-1.1%) 80 221189 223682 (+1.1%) 96 239807 246222 (+2.7%) 112 262135 271329 (+3.5%) 128 273612 286782 (+4.8%) 144 280009 293943 (+5.0%) 160 285972 299798 (+4.8%)
I'll review the patchset in detail, especially the cleanups and optimizations, when my wifi isn't so sketchy.
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