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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/util.c | |
| parent | 9800339b5e0f0e24ab3dac349e0de80d2018832e (diff) | |
| download | lwn-33806f06da654092182410d974b6d3c5396ea3eb.tar.gz lwn-33806f06da654092182410d974b6d3c5396ea3eb.zip | |
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/util.c')
| -rw-r--r-- | mm/util.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/mm/util.c b/mm/util.c index 16a73195a37b..ab1424dbe2e6 100644 --- a/mm/util.c +++ b/mm/util.c @@ -6,6 +6,7 @@ #include <linux/sched.h> #include <linux/security.h> #include <linux/swap.h> +#include <linux/swapops.h> #include <asm/uaccess.h> #include "internal.h" @@ -389,9 +390,12 @@ struct address_space *page_mapping(struct page *page) VM_BUG_ON(PageSlab(page)); #ifdef CONFIG_SWAP - if (unlikely(PageSwapCache(page))) - mapping = &swapper_space; - else + if (unlikely(PageSwapCache(page))) { + swp_entry_t entry; + + entry.val = page_private(page); + mapping = swap_address_space(entry); + } else #endif if ((unsigned long)mapping & PAGE_MAPPING_ANON) mapping = NULL; |