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| author | Pankaj Raghav <p.raghav@samsung.com> | 2024-01-15 11:25:22 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-02-22 10:24:38 -0800 |
| commit | e03c16fb4af1dfc615a4e1f51be0d5fe5840b904 (patch) | |
| tree | 706962b309671906187803f1bb0e26be724443dc /mm/readahead.c | |
| parent | cabbb6d51e2af4fc2f3c763f58a12c628f228987 (diff) | |
| download | linux-e03c16fb4af1dfc615a4e1f51be0d5fe5840b904.tar.gz linux-e03c16fb4af1dfc615a4e1f51be0d5fe5840b904.tar.bz2 linux-e03c16fb4af1dfc615a4e1f51be0d5fe5840b904.zip | |
readahead: use ilog2 instead of a while loop in page_cache_ra_order()
A while loop is used to adjust the new_order to be lower than the
ra->size. ilog2 could be used to do the same instead of using a loop.
ilog2 typically resolves to a bit scan reverse instruction. This is
particularly useful when ra->size is smaller than the 2^new_order as it
resolves in one instruction instead of looping to find the new_order.
No functional changes.
Link: https://lkml.kernel.org/r/20240115102523.2336742-1-kernel@pankajraghav.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/readahead.c')
| -rw-r--r-- | mm/readahead.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index 2648ec4f0494..1e74455f908e 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -500,10 +500,8 @@ void page_cache_ra_order(struct readahead_control *ractl, if (new_order < MAX_PAGECACHE_ORDER) { new_order += 2; - if (new_order > MAX_PAGECACHE_ORDER) - new_order = MAX_PAGECACHE_ORDER; - while ((1 << new_order) > ra->size) - new_order--; + new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order); + new_order = min_t(unsigned int, new_order, ilog2(ra->size)); } filemap_invalidate_lock_shared(mapping); |