[Devel] [PATCH rh7 6/8] ms/mm/memory-failure: share the i_mmap_rwsem

[Andrey Ryabinin]

From: Davidlohr Bueso <dave at stgolabs.net>

No brainer conversion: collect_procs_file() only schedules a process for
later kill, share the lock, similarly to the anon vma variant.

Signed-off-by: Davidlohr Bueso <dbueso at suse.de>
Acked-by: "Kirill A. Shutemov" <kirill at shutemov.name>
Acked-by: Hugh Dickins <hughd at google.com>
Cc: Oleg Nesterov <oleg at redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Cc: Rik van Riel <riel at redhat.com>
Cc: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman at suse.de>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>

https://jira.sw.ru/browse/PSBM-122663
(cherry picked from commit d28eb9c861f41aa2af4cfcc5eeeddff42b13d31e)
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 mm/memory-failure.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index da1ef2edd5dd..a5f5e604c0b8 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -497,7 +497,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
 	struct task_struct *tsk;
 	struct address_space *mapping = page->mapping;
 
-	i_mmap_lock_write(mapping);
+	i_mmap_lock_read(mapping);
 	qread_lock(&tasklist_lock);
 	for_each_process(tsk) {
 		pgoff_t pgoff = page_to_pgoff(page);
@@ -519,7 +519,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
 		}
 	}
 	qread_unlock(&tasklist_lock);
-	i_mmap_unlock_write(mapping);
+	i_mmap_unlock_read(mapping);
 }
 
 /*
-- 
2.26.2