Messages in this thread | | | Date | Mon, 15 Aug 2011 11:44:17 +0300 | From | Pekka Enberg <> | Subject | Re: [slub p4 0/7] slub: per cpu partial lists V4 |
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On 8/13/11 9:28 PM, David Rientjes wrote: > 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.
Andi, it'd be interesting to know your results for v4 of this patchset. I'm hoping to get the patches reviewed and merged to linux-next this week.
Pekka
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