From 33806f06da654092182410d974b6d3c5396ea3eb Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Fri, 22 Feb 2013 16:34:37 -0800 Subject: 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 Cc: Hugh Dickins Acked-by: Rik van Riel Acked-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index e97a0e5aea91..e51864e6fe8b 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -79,7 +79,7 @@ __try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset) struct page *page; int ret = 0; - page = find_get_page(&swapper_space, entry.val); + page = find_get_page(swap_address_space(entry), entry.val); if (!page) return 0; /* @@ -699,7 +699,8 @@ int free_swap_and_cache(swp_entry_t entry) p = swap_info_get(entry); if (p) { if (swap_entry_free(p, entry, 1) == SWAP_HAS_CACHE) { - page = find_get_page(&swapper_space, entry.val); + page = find_get_page(swap_address_space(entry), + entry.val); if (page && !trylock_page(page)) { page_cache_release(page); page = NULL; -- cgit v1.2.3