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| author | Chi Zhiling <chizhiling@kylinos.cn> | 2025-07-28 16:39:51 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-13 16:55:10 -0700 |
| commit | c4408277c0d773b7601def781702f7215f894ca7 (patch) | |
| tree | bba9f38e35d84bcd25150c675a5021b1d643bf03 /mm/filemap.c | |
| parent | f6a4a150f1ec2ef9a1241adc173d8a67ff19633f (diff) | |
| download | tip-c4408277c0d773b7601def781702f7215f894ca7.tar.gz | |
mm/filemap: do not use is_partially_uptodate for entire folio
Patch series "Tiny optimization for large read operations".
This series contains two patches,
1. Skip calling is_partially_uptodate for entire folio to save time, I
have reviewed the mpage and iomap implementations and didn't spot any
issues, but this change likely needs more thorough review.
2. Skip calling filemap_uptodate if there are ready folios in the
batch, This might save a few milliseconds in practice, but I didn't
observe measurable improvements in my tests.
This patch (of 2):
When a folio is marked as non-uptodate, it means the folio contains some
non-uptodate data. Therefore, calling is_partially_uptodate() to recheck
the entire folio is redundant.
If all data in a folio is actually up-to-date but the folio lacks the
uptodate flag, it will still be treated as non-uptodate in many other
places. Thus, there should be no special case handling for filemap.
Link: https://lkml.kernel.org/r/20250728083952.75518-1-chizhiling@163.com
Link: https://lkml.kernel.org/r/20250728083952.75518-2-chizhiling@163.com
Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index f3a6c24897f4ac..d6f95513241f02 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2447,6 +2447,9 @@ static bool filemap_range_uptodate(struct address_space *mapping, pos -= folio_pos(folio); } + if (pos == 0 && count >= folio_size(folio)) + return false; + return mapping->a_ops->is_partially_uptodate(folio, pos, count); } |