Messages in this thread | | | From | Daniel Phillips <> | Subject | Re: [PATCH] Rmap speedup | Date | Sun, 4 Aug 2002 00:49:27 +0200 |
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On Saturday 03 August 2002 23:40, Andrew Morton wrote: > - total amount of CPU time lost spinning on locks is 1%, mainly > in page_add_rmap and zap_pte_range. > > That's not much spintime. The total system time with this test went > from 71 seconds (2.5.26) to 88 seconds (2.5.30). (4.5 seconds per CPU) > So all the time is presumably spent waiting on cachelines to come from > other CPUs, or from local L2.
Have we tried this one:
static inline unsigned rmap_lockno(pgoff_t index) { - return (index >> 4) & (ARRAY_SIZE(rmap_locks) - 1); + return (index >> 4) & (ARRAY_SIZE(rmap_locks) - 16); }
(which puts all the rmap spinlocks in separate cache lines)
-- Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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