malloc: Avoid premature fallback to mmap [BZ #20284]
Commit Message
2016-06-21 Florian Weimer <fweimer@redhat.com>
[BZ #20284]
* malloc/arena.c (reused_arena): Do not return NULL if we start
out with a non-corrupted arena.
Comments
On Tue, Jun 21, 2016 at 05:21:18PM +0200, Florian Weimer wrote:
> 2016-06-21 Florian Weimer <fweimer@redhat.com>
>
> [BZ #20284]
> * malloc/arena.c (reused_arena): Do not return NULL if we start
> out with a non-corrupted arena.
>
Looks OK to me. The commit log could however use a nice explanation
of what the problem is.
Siddhesh
@@ -771,14 +771,12 @@ reused_arena (mstate avoid_arena)
{
result = result->next;
if (result == begin)
- break;
+ /* We looped around the arena list. We could not find any
+ arena that was either not corrupted or not the one we
+ wanted to avoid. */
+ return NULL;
}
- /* We could not find any arena that was either not corrupted or not the one
- we wanted to avoid. */
- if (result == begin || result == avoid_arena)
- return NULL;
-
/* No arena available without contention. Wait for the next in line. */
LIBC_PROBE (memory_arena_reuse_wait, 3, &result->mutex, result, avoid_arena);
(void) mutex_lock (&result->mutex);