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| author | Shaohua Li <shli@kernel.org> | 2013-02-22 16:34:37 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-23 17:50:17 -0800 |
| commit | 33806f06da654092182410d974b6d3c5396ea3eb (patch) | |
| tree | 7f7da99d94481a1d4c78ebf05b410fc8ba654a39 /mm/swap.c | |
| parent | 9800339b5e0f0e24ab3dac349e0de80d2018832e (diff) | |
| download | linux-33806f06da654092182410d974b6d3c5396ea3eb.tar.gz | |
swap: make each swap partition have one address_space
When I use several fast SSD to do swap, swapper_space.tree_lock is heavily contended. This makes each swap partition have one address_space to reduce the lock contention. There is an array of address_space for swap. The swap entry type is the index to the array. In my test with 3 SSD, this increases the swapout throughput 20%. [akpm@linux-foundation.org: revert unneeded change to __add_to_swap_cache] Signed-off-by: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swap.c')
| -rw-r--r-- | mm/swap.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/mm/swap.c b/mm/swap.c index 6310dc2008ff..8a529a01e8fc 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -855,9 +855,14 @@ EXPORT_SYMBOL(pagevec_lookup_tag); void __init swap_setup(void) { unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT); - #ifdef CONFIG_SWAP - bdi_init(swapper_space.backing_dev_info); + int i; + + bdi_init(swapper_spaces[0].backing_dev_info); + for (i = 0; i < MAX_SWAPFILES; i++) { + spin_lock_init(&swapper_spaces[i].tree_lock); + INIT_LIST_HEAD(&swapper_spaces[i].i_mmap_nonlinear); + } #endif /* Use a smaller cluster for small-memory machines */ |