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| author | Huang Ying <ying.huang@intel.com> | 2017-09-07 01:22:34 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-07 02:27:28 +0200 |
| commit | 59807685a7e77e8c8fe5925613968841538d53d7 (patch) | |
| tree | c2827c8a22e600f36258d6137a131a7150577b72 /mm/huge_memory.c | |
| parent | mm: test code to write THP to swap device as a whole (diff) | |
| download | linux-59807685a7e77e8c8fe5925613968841538d53d7.tar.xz linux-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 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 02dfe635c9fe..772048c233d1 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2481,6 +2481,9 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageCompound(page), page); + if (PageWriteback(page)) + return -EBUSY; + if (PageAnon(head)) { /* * The caller does not necessarily hold an mmap_sem that would @@ -2558,7 +2561,12 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) __dec_node_page_state(page, NR_SHMEM_THPS); spin_unlock(&pgdata->split_queue_lock); __split_huge_page(page, list, flags); - ret = 0; + if (PageSwapCache(head)) { + swp_entry_t entry = { .val = page_private(head) }; + + ret = split_swap_cluster(entry); + } else + ret = 0; } else { if (IS_ENABLED(CONFIG_DEBUG_VM) && mapcount) { pr_alert("total_mapcount: %u, page_count(): %u\n", |