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| author | Tim Chen <tim.c.chen@linux.intel.com> | 2017-02-22 15:45:29 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-22 16:41:30 -0800 |
| commit | e8c26ab60598558ec3a626e7925b06e7417d7710 (patch) | |
| tree | 7c4c14cea8fed4f82e56c5e4de89109cd642c0bc /include/linux/swap.h | |
| parent | 4b3ef9daa4fc0bba742a79faecb17fdaaead083b (diff) | |
| download | lwn-e8c26ab60598558ec3a626e7925b06e7417d7710.tar.gz lwn-e8c26ab60598558ec3a626e7925b06e7417d7710.zip | |
mm/swap: skip readahead for unreferenced swap slots
We can avoid needlessly allocating page for swap slots that are not used
by anyone. No pages have to be read in for these slots.
Link: http://lkml.kernel.org/r/0784b3f20b9bd3aa5552219624cb78dc4ae710c9.1484082593.git.tim.c.chen@linux.intel.com
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net> escreveu:
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
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 | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 648a32b58e3e..3116382067cd 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -398,6 +398,7 @@ extern unsigned int count_swap_pages(int, int); extern sector_t map_swap_page(struct page *, struct block_device **); extern sector_t swapdev_block(int, pgoff_t); extern int page_swapcount(struct page *); +extern int __swp_swapcount(swp_entry_t entry); extern int swp_swapcount(swp_entry_t entry); extern struct swap_info_struct *page_swap_info(struct page *); extern bool reuse_swap_page(struct page *, int *); @@ -492,6 +493,11 @@ static inline int page_swapcount(struct page *page) return 0; } +static inline int __swp_swapcount(swp_entry_t entry) +{ + return 0; +} + static inline int swp_swapcount(swp_entry_t entry) { return 0; |