diff options
author | Rik van Riel <riel@redhat.com> | 2012-03-21 23:33:50 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-22 00:54:56 (GMT) |
commit | 67f96aa252e606cdf6c3cf1032952ec207ec0cf0 (patch) | |
tree | a5a4299dd32789831eda558b51c0120272846664 /mm/vmscan.c | |
parent | c38446cc65e1f2b3eb8630c53943b94c4f65f670 (diff) | |
download | linux-67f96aa252e606cdf6c3cf1032952ec207ec0cf0.tar.xz |
mm: make swapin readahead skip over holes
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.
The checks done in valid_swaphandles are already done in
read_swap_cache_async as well, allowing us to remove a fair amount of
code.
[akpm@linux-foundation.org: fix it for page_cluster >= 32]
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Adrian Drzewiecki <z@drze.net>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
0 files changed, 0 insertions, 0 deletions