Liu Shixin 5c46d5319b mm/filemap: don't decrease mmap_miss when folio has workingset flag
If there are too many folios that are recently evicted in a file, then
they will probably continue to be evicted.  In such situation, there is no
positive effect to read-ahead this file since it is only a waste of IO.

The mmap_miss is increased in do_sync_mmap_readahead() and decreased in
both do_async_mmap_readahead() and filemap_map_pages().  In order to skip
read-ahead in above scenario, the mmap_miss have to increased exceed
MMAP_LOTSAMISS.  This can be done by stop decreased mmap_miss when folio
has workingset flag.  The async path is not to care because in above
scenario, it's hard to run into the async path.

[liushixin2@huawei.com: add comments]
  Link: https://lkml.kernel.org/r/20240326065026.1910584-1-liushixin2@huawei.com
Link: https://lkml.kernel.org/r/20240322093555.226789-3-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jinjiang Tu <tujinjiang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:07 -07:00
..
2024-04-25 20:55:49 -07:00
2024-03-11 09:38:17 -07:00
2023-12-12 10:11:32 +01:00
2024-03-21 14:41:00 -07:00
2023-04-12 17:36:23 -07:00
2024-02-24 15:53:40 -08:00
2022-10-03 14:02:43 -07:00
2024-03-22 10:41:13 -07:00
2024-02-21 16:00:03 -08:00
2024-04-25 20:56:00 -07:00
2023-04-12 17:36:23 -07:00
2024-04-25 20:55:48 -07:00
2024-04-25 20:55:48 -07:00
2024-04-25 20:55:48 -07:00