The commit is pushed to "branch-rh7-3.10.0-514.26.1.vz7.35.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-514.26.1.vz7.33.22
------>
commit 1c7e7932ba7de7636e02a32d88f365bcc0f2a2b1
Author: Hugh Dickins <hu...@google.com>
Date: Mon Aug 7 13:40:52 2017 +0400
ms/mm: fix sleeping function warning from __put_anon_vma
Trinity reports BUG:
sleeping function called from invalid context at kernel/locking/rwsem.c:47
in_atomic(): 0, irqs_disabled(): 0, pid: 5787, name: trinity-c27
__might_sleep < down_write < __put_anon_vma < page_get_anon_vma <
migrate_pages < compact_zone < compact_zone_order < try_to_compact_pages ..
Right, since conversion to mutex then rwsem, we should not put_anon_vma()
from inside an rcu_read_lock()ed section: fix the two places that did so.
And add might_sleep() to anon_vma_free(), as suggested by Peter Zijlstra.
Fixes: 88c22088bf23 ("mm: optimize page_lock_anon_vma() fast-path")
Reported-by: Dave Jones <da...@redhat.com>
Signed-off-by: Hugh Dickins <hu...@google.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: <sta...@vger.kernel.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Backport of ms commit 7f39dda ("mm: fix sleeping function warning from
__put_anon_vma")
Found in scope of https://jira.sw.ru/browse/PSBM-65033
Signed-off-by: Stanislav Kinsburskiy <skinsbur...@virtuozzo.com>
---
mm/rmap.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 4668df5..f3aac5a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -110,6 +110,7 @@ static inline void anon_vma_free(struct anon_vma *anon_vma)
* LOCK should suffice since the actual taking of the lock must
* happen _before_ what follows.
*/
+ might_sleep();
if (rwsem_is_locked(&anon_vma->root->rwsem)) {
anon_vma_lock_write(anon_vma);
anon_vma_unlock_write(anon_vma);
@@ -480,8 +481,9 @@ struct anon_vma *page_get_anon_vma(struct page *page)
* above cannot corrupt).
*/
if (!page_mapped(page)) {
+ rcu_read_unlock();
put_anon_vma(anon_vma);
- anon_vma = NULL;
+ return NULL;
}
out:
rcu_read_unlock();
@@ -531,9 +533,9 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page)
}
if (!page_mapped(page)) {
+ rcu_read_unlock();
put_anon_vma(anon_vma);
- anon_vma = NULL;
- goto out;
+ return NULL;
}
/* we pinned the anon_vma, its safe to sleep */
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