Subject: [merged] mm-fix-sleeping-function-warning-from-__put_anon_vma.patch 
removed from -mm tree
To: 
[email protected],[email protected],[email protected],[email protected],[email protected]
From: [email protected]
Date: Thu, 05 Jun 2014 12:41:57 -0700


The patch titled
     Subject: mm: fix sleeping function warning from __put_anon_vma
has been removed from the -mm tree.  Its filename was
     mm-fix-sleeping-function-warning-from-__put_anon_vma.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Hugh Dickins <[email protected]>
Subject: 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 <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 mm/rmap.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff -puN mm/rmap.c~mm-fix-sleeping-function-warning-from-__put_anon_vma 
mm/rmap.c
--- a/mm/rmap.c~mm-fix-sleeping-function-warning-from-__put_anon_vma
+++ a/mm/rmap.c
@@ -103,6 +103,7 @@ static inline void anon_vma_free(struct
         * 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);
@@ -426,8 +427,9 @@ struct anon_vma *page_get_anon_vma(struc
         * above cannot corrupt).
         */
        if (!page_mapped(page)) {
+               rcu_read_unlock();
                put_anon_vma(anon_vma);
-               anon_vma = NULL;
+               return NULL;
        }
 out:
        rcu_read_unlock();
@@ -477,9 +479,9 @@ struct anon_vma *page_lock_anon_vma_read
        }
 
        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 */
_

Patches currently in -mm which might be from [email protected] are

origin.patch
linux-next.patch
memcg-mm-introduce-lowlimit-reclaim.patch
memcg-mm-introduce-lowlimit-reclaim-fix.patch
memcg-mm-introduce-lowlimit-reclaim-fix2patch.patch
memcg-allow-setting-low_limit.patch
memcg-doc-clarify-global-vs-limit-reclaims.patch
memcg-doc-clarify-global-vs-limit-reclaims-fix.patch
memcg-document-memorylow_limit_in_bytes.patch
vmscan-memcg-check-whether-the-low-limit-should-be-ignored.patch
vmscan-memcg-always-use-swappiness-of-the-reclaimed-memcg-swappiness-and-o-om-control-fixpatch.patch
mm-replace-remap_file_pages-syscall-with-emulation-fix-3.patch

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to