The patch titled
Subject: mm/filemap.c: remove redundant test from find_get_pages_contig
has been added to the -mm tree. Its filename is
mm-remove-redundant-test-from-find_get_pages_contig.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-remove-redundant-test-from-find_get_pages_contig.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-remove-redundant-test-from-find_get_pages_contig.patch
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------------------------------------------------------
From: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Subject: mm/filemap.c: remove redundant test from find_get_pages_contig
After we establish a reference on the page, we check the pointer continues
to be in the correct position in i_pages. There's no need to check the
page->mapping or page->index afterwards; if those can change after we've
got the reference, they can change after we return the page to the caller.
Link: http://lkml.kernel.org/r/20190107200224.13260-1-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 10 ----------
1 file changed, 10 deletions(-)
--- a/mm/filemap.c~mm-remove-redundant-test-from-find_get_pages_contig
+++ a/mm/filemap.c
@@ -1837,16 +1837,6 @@ unsigned find_get_pages_contig(struct ad
if (unlikely(page != xas_reload(&xas)))
goto put_page;
- /*
- * must check mapping and index after taking the ref.
- * otherwise we can get both false positives and false
- * negatives, which is just confusing to the caller.
- */
- if (!page->mapping || page_to_pgoff(page) != xas.xa_index) {
- put_page(page);
- break;
- }
-
pages[ret] = page;
if (++ret == nr_pages)
break;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
initialise-mmu_notifier_range-correctly.patch
mm-remove-sysctl_extfrag_handler.patch
mm-remove-redundant-test-from-find_get_pages_contig.patch
