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| author | Gavin Shan <gshan@redhat.com> | 2024-06-27 10:39:50 +1000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-07-03 22:40:37 -0700 |
| commit | 1f789a45c3f1aa77531db21768fca70b66c0eeb1 (patch) | |
| tree | bb1ab1acb70b84c781957e0200c086438b8d6a07 /mm/readahead.c | |
| parent | 099d90642a711caae377f53309abfe27e8724a8b (diff) | |
| download | linux-1f789a45c3f1aa77531db21768fca70b66c0eeb1.tar.gz linux-1f789a45c3f1aa77531db21768fca70b66c0eeb1.tar.bz2 linux-1f789a45c3f1aa77531db21768fca70b66c0eeb1.zip | |
mm/readahead: limit page cache size in page_cache_ra_order()
In page_cache_ra_order(), the maximal order of the page cache to be
allocated shouldn't be larger than MAX_PAGECACHE_ORDER. Otherwise, it's
possible the large page cache can't be supported by xarray when the
corresponding xarray entry is split.
For example, HPAGE_PMD_ORDER is 13 on ARM64 when the base page size is
64KB. The PMD-sized page cache can't be supported by xarray.
Link: https://lkml.kernel.org/r/20240627003953.1262512-3-gshan@redhat.com
Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zhenyu Zhang <zhenyzha@redhat.com>
Cc: <stable@vger.kernel.org> [5.18+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/readahead.c')
| -rw-r--r-- | mm/readahead.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index c1b23989d9ca..817b2a352d78 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -503,11 +503,11 @@ void page_cache_ra_order(struct readahead_control *ractl, limit = min(limit, index + ra->size - 1); - if (new_order < MAX_PAGECACHE_ORDER) { + if (new_order < MAX_PAGECACHE_ORDER) new_order += 2; - new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order); - new_order = min_t(unsigned int, new_order, ilog2(ra->size)); - } + + new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order); + new_order = min_t(unsigned int, new_order, ilog2(ra->size)); /* See comment in page_cache_ra_unbounded() */ nofs = memalloc_nofs_save(); |