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| author | Liu Shixin <liushixin2@huawei.com> | 2024-03-22 10:35:55 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-04-26 05:56:07 +0200 |
| commit | 5c46d5319bde73075c5f2cefd555426848eb506f (patch) | |
| tree | 7a3bf0df6f60b43db4c0832d091b3b7df1061822 /mm/filemap.c | |
| parent | mm/readahead: break read-ahead loop if filemap_add_folio return -ENOMEM (diff) | |
| download | linux-5c46d5319bde73075c5f2cefd555426848eb506f.tar.xz linux-5c46d5319bde73075c5f2cefd555426848eb506f.zip | |
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>
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 60890758d660..480ae6589803 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3492,7 +3492,15 @@ static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf, if (PageHWPoison(page + count)) goto skip; - (*mmap_miss)++; + /* + * If there are too many folios that are recently evicted + * in a file, they will probably continue to be evicted. + * In such situation, read-ahead is only a waste of IO. + * Don't decrease mmap_miss in this scenario to make sure + * we can stop read-ahead. + */ + if (!folio_test_workingset(folio)) + (*mmap_miss)++; /* * NOTE: If there're PTE markers, we'll leave them to be @@ -3541,7 +3549,9 @@ static vm_fault_t filemap_map_order0_folio(struct vm_fault *vmf, if (PageHWPoison(page)) return ret; - (*mmap_miss)++; + /* See comment of filemap_map_folio_range() */ + if (!folio_test_workingset(folio)) + (*mmap_miss)++; /* * NOTE: If there're PTE markers, we'll leave them to be |