diff options
| author | Frederick Mayle <fmayle@google.com> | 2026-05-12 13:31:36 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-05-28 21:31:00 -0700 |
| commit | 9c0066df0e3ee4ecd4688ecf1c888d7c3e206382 (patch) | |
| tree | 6dccd72f886726f5c90c6f03741dfa50881365fa /mm | |
| parent | 070118942ebcb9040db31f76f24c9a2ea0e05dda (diff) | |
| download | linux-next-history-9c0066df0e3ee4ecd4688ecf1c888d7c3e206382.tar.gz | |
mm/readahead: simplify page_cache_ra_unbounded loop counter reset
Minor cleanup, no behavior change intended.
`read_pages` ensures that `ractl->_nr_pages` is zero before it returns, so
the `ractl->_nr_pages` term in these expressions contributes nothing.
This seems to have been true since the statements were introduced in
commit f615bd5c4725f ("mm/readahead: Handle ractl nr_pages being
modified").
The new expression has an intuitive explanation. When filesystems perform
readahead, they increment `ractl->_index` by the number of pages
processed, so, after `read_pages` returns, `ractl->_index` points to the
first page after those already processed. `index` points to the first
page considered in the loop. So, `ractl->_index - index` is the number of
pages processed by the loop so far.
Link: https://lore.kernel.org/20260512203154.754075-3-fmayle@google.com
Signed-off-by: Frederick Mayle <fmayle@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/readahead.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index 23bec54973084..42f2f20633b0b 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -281,7 +281,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, */ read_pages(ractl); ractl->_index += min_nrpages; - i = ractl->_index + ractl->_nr_pages - index; + i = ractl->_index - index; continue; } @@ -297,7 +297,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, break; read_pages(ractl); ractl->_index += min_nrpages; - i = ractl->_index + ractl->_nr_pages - index; + i = ractl->_index - index; continue; } if (i == mark) |