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| author | Huang Ying <ying.huang@intel.com> | 2017-09-06 16:22:34 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-06 17:27:28 -0700 |
| commit | 59807685a7e77e8c8fe5925613968841538d53d7 (patch) | |
| tree | c2827c8a22e600f36258d6137a131a7150577b72 /include/linux/swap.h | |
| parent | 225311a46411c37e20e73d99f4382f141e12f6f9 (diff) | |
| download | lwn-59807685a7e77e8c8fe5925613968841538d53d7.tar.gz lwn-59807685a7e77e8c8fe5925613968841538d53d7.zip | |
mm, THP, swap: support splitting THP for THP swap out
After adding swapping out support for THP (Transparent Huge Page), it is
possible that a THP in swap cache (partly swapped out) need to be split.
To split such a THP, the swap cluster backing the THP need to be split
too, that is, the CLUSTER_FLAG_HUGE flag need to be cleared for the swap
cluster. The patch implemented this.
And because the THP swap writing needs the THP keeps as huge page during
writing. The PageWriteback flag is checked before splitting.
Link: http://lkml.kernel.org/r/20170724051840.2309-8-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c]
Cc: Vishal L Verma <vishal.l.verma@intel.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 | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 7176ba780e83..461cf107ad52 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -527,6 +527,15 @@ static inline swp_entry_t get_swap_page(struct page *page) #endif /* CONFIG_SWAP */ +#ifdef CONFIG_THP_SWAP +extern int split_swap_cluster(swp_entry_t entry); +#else +static inline int split_swap_cluster(swp_entry_t entry) +{ + return 0; +} +#endif + #ifdef CONFIG_MEMCG static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) { |