Messages in this thread | | | From | Con Kolivas <> | Subject | Re: -mm seems significanty slower than mainline on kernbench | Date | Thu, 12 Jan 2006 01:29:15 +1100 |
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On Wednesday 11 January 2006 23:24, Peter Williams wrote: > Martin J. Bligh wrote: > > That seems broken to me ? > > But, yes, given that the problem goes away when the patch is removed > (which we're still waiting to see) it's broken. I think the problem is > probably due to the changed metric (i.e. biased load instead of simple > load) causing idle_balance() to fail more often (i.e. it decides to not > bother moving any tasks more often than it otherwise would) which would > explain the increased idle time being seen. This means that the fix > would be to review the criteria for deciding whether to move tasks in > idle_balance().
Look back on my implementation. The problem as I saw it was that one task alone with a biased load would suddenly make a runqueue look much busier than it was supposed to so I special cased the runqueue that had precisely one task.
Cheers, Con - 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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