diff options
| author | Matthew Wilcox (Oracle) | 2020-04-06 20:04:31 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2020-04-07 10:43:38 -0700 |
| commit | a0650604a707b1926cbc32feb2f006ebb74ef47b (patch) | |
| tree | 9ccf2f46cb62ab402dd3d028f0b984ae97d40a1f | |
| parent | 85b9f46e8ea451633ccd60a7d8cacbfff9f34047 (diff) | |
include/linux/pagemap.h: optimise find_subpage for !THP
If THP is disabled, find_subpage() can become a no-op by using
hpage_nr_pages() instead of compound_nr(). hpage_nr_pages() embeds a
check for PageTail, so we can drop the check here.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200318140253.6141-5-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/pagemap.h | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index f56282491a48..a8f7bd8ea1c6 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -341,9 +341,7 @@ static inline struct page *find_subpage(struct page *head, pgoff_t index) if (PageHuge(head)) return head; - VM_BUG_ON_PAGE(PageTail(head), head); - - return head + (index & (compound_nr(head) - 1)); + return head + (index & (hpage_nr_pages(head) - 1)); } struct page *find_get_entry(struct address_space *mapping, pgoff_t offset); |