Messages in this thread | | | Date | Thu, 30 Aug 2007 15:55:01 +0200 | From | Helge Hafting <> | Subject | Re: speeding up swapoff |
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Robert Hancock wrote: > Daniel Drake wrote: >> On Wed, 2007-08-29 at 07:30 -0700, Arjan van de Ven wrote: >>>> My experiments show that when there is not much free physical memory, >>>> swapoff moves pages out of swap at a rate of approximately 5mb/sec. >>> sounds like about disk speed (at random-seek IO pattern) >> >> We are only using 'standard' seagate SATA disks, but I would have >> thought much more performance (40+ mb/sec) would be reachable. > > Not if it is doing random seeks.. If the swap device is full, then there is no need for random seeks as the swap pages can be read in disk order. A not so full swap will skip over the unused areas, the time needed should still be limited to the time needed for reading the whole swap device.
If this optimization is worth it is another problem though.
Helge Hafting - 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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