Messages in this thread | | | Date | Wed, 10 Dec 2003 23:44:46 +0100 | From | Andrea Arcangeli <> | Subject | Re: 2.6.0-test9 - poor swap performance on low end machines |
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On Wed, Dec 10, 2003 at 11:05:25PM +0100, Roger Luethi wrote: > On Wed, 10 Dec 2003 22:52:35 +0100, Andrea Arcangeli wrote: > > On Mon, Dec 08, 2003 at 12:48:17PM -0800, William Lee Irwin III wrote: > > > qsbench I'd pretty much ignore except as a control case, since there's > > > nothing to do with a single process but let it thrash. > > > > this is not the point. If a single process like qsbench trashes twice as > > fast in 2.4, it means 2.6 has some great problem in the core vm, the > > whole point of swap is to trash but to give the task more physical > > virtual memory. I doubt you can solve it with anything returned by > > si_swapinfo. > > Uhm.. guys? I forgot to mention that earlier: qsbench as I used it was not > about one single process. There were four worker processes (-p 4), and my > load control stuff did make it run faster, so the point is moot.
more processes can be optimized even better by adding unfariness. Either ways a significant slowdown of qsbench probably means worse core VM, at least if compared with 2.4 that isn't adding huge unfariness just to optimize qsbench.
> Also, the 2.6 core VM doesn't seem all that bad since it was introduced in > 2.5.27 but most of the problems I measured were introduced after 2.5.40. > Check out the graph I posted.
you're confusing rmap with core vm. rmap in no way can be defined as the core vm, rmap is just a method used by the core vm to find some information more efficiently at the expenses of all the fast paths that now have to do the rmap bookkeeping. - 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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