diff options
| author | Rik van Riel <riel@redhat.com> | 2012-03-21 16:33:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-21 17:54:56 -0700 |
| commit | 67f96aa252e606cdf6c3cf1032952ec207ec0cf0 (patch) | |
| tree | a5a4299dd32789831eda558b51c0120272846664 /include | |
| parent | c38446cc65e1f2b3eb8630c53943b94c4f65f670 (diff) | |
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 'include')
| -rw-r--r-- | include/linux/swap.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 3e60228e729..64a7dba6784 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -329,7 +329,6 @@ extern long total_swap_pages; extern void si_swapinfo(struct sysinfo *); extern swp_entry_t get_swap_page(void); extern swp_entry_t get_swap_page_of_type(int); -extern int valid_swaphandles(swp_entry_t, unsigned long *); extern int add_swap_count_continuation(swp_entry_t, gfp_t); extern void swap_shmem_alloc(swp_entry_t); extern int swap_duplicate(swp_entry_t); |