From 96888e0ab0e652eb3036eff0cb0664a96cb7e9a9 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Thu, 25 Feb 2021 17:15:29 -0800
Subject: [PATCH] mm/shmem: use pagevec_lookup in shmem_unlock_mapping
The comment shows that the reason for using find_get_entries() is now
stale; find_get_pages() will not return 0 if it hits a consecutive run of
swap entries, and I don't believe it has since 2011. pagevec_lookup() is
a simpler function to use than find_get_pages(), so use it instead.
Link: https://lkml.kernel.org/r/20201112212641.27837-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/shmem.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index ff741d2297016..5ea1fa53db3fa 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -842,7 +842,6 @@ unsigned long shmem_swap_usage(struct vm_area_struct *vma)
void shmem_unlock_mapping(struct address_space *mapping)
{
struct pagevec pvec;
- pgoff_t indices[PAGEVEC_SIZE];
pgoff_t index = 0;
pagevec_init(&pvec);
@@ -850,16 +849,8 @@ void shmem_unlock_mapping(struct address_space *mapping)
* Minor point, but we might as well stop if someone else SHM_LOCKs it.
*/
while (!mapping_unevictable(mapping)) {
- /*
- * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it
- * has finished, if it hits a row of PAGEVEC_SIZE swap entries.
- */
- pvec.nr = find_get_entries(mapping, index,
- PAGEVEC_SIZE, pvec.pages, indices);
- if (!pvec.nr)
+ if (!pagevec_lookup(&pvec, mapping, &index))
break;
- index = indices[pvec.nr - 1] + 1;
- pagevec_remove_exceptionals(&pvec);
check_move_unevictable_pages(&pvec);
pagevec_release(&pvec);
cond_resched();
--
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