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    SubjectRe: [PATCH -mm] make swapin readahead skip over holes
    (1/9/12 6:10 PM), Rik van Riel wrote:
    > Ever since abandoning the virtual scan of processes, for scalability
    > reasons, swap space has been a little more fragmented than before.
    > This can lead to the situation where a large memory user is killed,
    > swap space ends up full of "holes" and swapin readahead is totally
    > ineffective.
    > On my home system, after killing a leaky firefox it took over an
    > hour to page just under 2GB of memory back in, slowing the virtual
    > machines down to a crawl.
    > This patch makes swapin readahead simply skip over holes, instead
    > of stopping at them. This allows the system to swap things back in
    > at rates of several MB/second, instead of a few hundred kB/second.

    If I understand correctly, this patch have

    - increase IO throughput
    - increase a risk to pick up unrelated swap entries by swap readahead

    The changelog explained former but doesn't explained latter. I'm a bit
    hesitate now.

     \ /
      Last update: 2012-01-10 00:53    [W:0.020 / U:6.108 seconds]
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