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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 /include/linux/swap.h | |
| 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 'include/linux/swap.h')
| -rw-r--r-- | include/linux/swap.h | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 8c66486a8ca8..235c039892ee 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -8,7 +8,7 @@ #include <linux/memcontrol.h> #include <linux/sched.h> #include <linux/node.h> - +#include <linux/fs.h> #include <linux/atomic.h> #include <asm/page.h> @@ -330,8 +330,9 @@ int generic_swapfile_activate(struct swap_info_struct *, struct file *, sector_t *); /* linux/mm/swap_state.c */ -extern struct address_space swapper_space; -#define total_swapcache_pages swapper_space.nrpages +extern struct address_space swapper_spaces[]; +#define swap_address_space(entry) (&swapper_spaces[swp_type(entry)]) +extern unsigned long total_swapcache_pages(void); extern void show_swap_cache_info(void); extern int add_to_swap(struct page *); extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); @@ -382,7 +383,7 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) #define nr_swap_pages 0L #define total_swap_pages 0L -#define total_swapcache_pages 0UL +#define total_swapcache_pages() 0UL #define si_swapinfo(val) \ do { (val)->freeswap = (val)->totalswap = 0; } while (0) |