Messages in this thread | | | Date | Fri, 20 Mar 2009 12:04:42 -0400 (EDT) | From | Christoph Lameter <> | Subject | Re: [PATCH 00/25] Cleanup and optimise the page allocator V5 |
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On Fri, 20 Mar 2009, Mel Gorman wrote:
> hmm, I'm missing something in your reasoning. The contention I saw for > zone->lru_lock > > &zone->lru_lock 37350 [<ffffffff8029d6fe>] ____pagevec_lru_add+0x9c/0x172 > &zone->lru_lock 55423 [<ffffffff8029d377>] release_pages+0x10a/0x21b > &zone->lru_lock 402 [<ffffffff8029d9d9>] activate_page+0x4f/0x147 > &zone->lru_lock 6 [<ffffffff8029dbbd>] put_page+0x94/0x122 > > So I just assumed it was LRU pages being taken off and freed that was > causing the contention. Can SLUB affect that?
No. But it can affect the taking of the zone lock.
> Maybe you meant zone->lock and SLUB could tune buffers more to avoid > that if that lock was hot. That is one alternative but the later patches > proposed an alternative whereby high-order and compound pages could be > stored on the PCP lists. Compound only really helps SLUB but high-order > also helped stacks, signal handlers and the like so it seemed like a > good idea one way or the other. Course, this meant a search of the PCP > lists or increasing the size of the PCP structure - swings and > roundabouts :/
Maybe include those as well? Its good stuff.
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