cpusets: update mems allowed in page allocator
If all allowable memory is unreclaimable, it is possible to loop forever
in the page allocator for ~__GFP_NORETRY allocations.
During this time, it is also possible for a task's cpuset to expand its
set of allowable nodes so that it now includes free memory. The cached
copy of this set, current->mems_allowed, is stale, however, since there
has not been a subsequent call to cpuset_update_task_memory_state().
The cached copy of the set of allowable nodes is now updated in the page
allocator's slow path so the additional memory is available to
get_page_from_freelist().
[akpm@linux-foundation.org: add comment]
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Paul Menage <menage@google.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 54069e6..d8ac014 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1561,6 +1561,10 @@
/* We now go into synchronous reclaim */
cpuset_memory_pressure_bump();
+ /*
+ * The task's cpuset might have expanded its set of allowable nodes
+ */
+ cpuset_update_task_memory_state();
p->flags |= PF_MEMALLOC;
reclaim_state.reclaimed_slab = 0;
p->reclaim_state = &reclaim_state;