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| author |   Minchan Kim <minchan@kernel.org> | 2017-11-15 17:33:11 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 18:21:02 -0800 |
| commit | aa8d22a11da933dbf880b4933b58931f4aefe91c (patch) | |
| tree | ed7a7c1ecdfa4da6079858dfc0cfb6fbb65e3286 /mm/swap_state.c | |
| parent | mm, swap: skip swapcache for swapin of synchronous device (diff) | |
| download | linux-dev-aa8d22a11da933dbf880b4933b58931f4aefe91c.tar.xz linux-dev-aa8d22a11da933dbf880b4933b58931f4aefe91c.zip | |
mm: swap: SWP_SYNCHRONOUS_IO: skip swapcache only if swapped page has no other reference
When SWP_SYNCHRONOUS_IO swapped-in pages are shared by several
processes, it can cause unnecessary memory wastage by skipping swap
cache. Because, with swapin fault by read, they could share a page if
the page were in swap cache. Thus, it avoids allocating same content
new pages.
This patch makes the swapcache skipping work only if the swap pte is
non-sharable.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1507620825-5537-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swap_state.c')
0 files changed, 0 insertions, 0 deletions