oom-kill: fix NUMA constraint check with nodemask
Fix node-oriented allocation handling in oom-kill.c I myself think of this
as a bugfix not as an ehnancement.
In these days, things are changed as
- alloc_pages() eats nodemask as its arguments, __alloc_pages_nodemask().
- mempolicy don't maintain its own private zonelists.
(And cpuset doesn't use nodemask for __alloc_pages_nodemask())
So, current oom-killer's check function is wrong.
This patch does
- check nodemask, if nodemask && nodemask doesn't cover all
node_states[N_HIGH_MEMORY], this is CONSTRAINT_MEMORY_POLICY.
- Scan all zonelist under nodemask, if it hits cpuset's wall
this faiulre is from cpuset.
And
- modifies the caller of out_of_memory not to call oom if __GFP_THISNODE.
This doesn't change "current" behavior. If callers use __GFP_THISNODE
it should handle "page allocation failure" by itself.
- handle __GFP_NOFAIL+__GFP_THISNODE path.
This is something like a FIXME but this gfpmask is not used now.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 6bb8a7a..25c679e 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -196,27 +196,46 @@
/*
* Determine the type of allocation constraint.
*/
-static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,
- gfp_t gfp_mask)
-{
#ifdef CONFIG_NUMA
+static enum oom_constraint constrained_alloc(struct zonelist *zonelist,
+ gfp_t gfp_mask, nodemask_t *nodemask)
+{
struct zone *zone;
struct zoneref *z;
enum zone_type high_zoneidx = gfp_zone(gfp_mask);
- nodemask_t nodes = node_states[N_HIGH_MEMORY];
- for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
- if (cpuset_zone_allowed_softwall(zone, gfp_mask))
- node_clear(zone_to_nid(zone), nodes);
- else
- return CONSTRAINT_CPUSET;
+ /*
+ * Reach here only when __GFP_NOFAIL is used. So, we should avoid
+ * to kill current.We have to random task kill in this case.
+ * Hopefully, CONSTRAINT_THISNODE...but no way to handle it, now.
+ */
+ if (gfp_mask & __GFP_THISNODE)
+ return CONSTRAINT_NONE;
- if (!nodes_empty(nodes))
+ /*
+ * The nodemask here is a nodemask passed to alloc_pages(). Now,
+ * cpuset doesn't use this nodemask for its hardwall/softwall/hierarchy
+ * feature. mempolicy is an only user of nodemask here.
+ * check mempolicy's nodemask contains all N_HIGH_MEMORY
+ */
+ if (nodemask && !nodes_subset(node_states[N_HIGH_MEMORY], *nodemask))
return CONSTRAINT_MEMORY_POLICY;
-#endif
+
+ /* Check this allocation failure is caused by cpuset's wall function */
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ high_zoneidx, nodemask)
+ if (!cpuset_zone_allowed_softwall(zone, gfp_mask))
+ return CONSTRAINT_CPUSET;
return CONSTRAINT_NONE;
}
+#else
+static enum oom_constraint constrained_alloc(struct zonelist *zonelist,
+ gfp_t gfp_mask, nodemask_t *nodemask)
+{
+ return CONSTRAINT_NONE;
+}
+#endif
/*
* Simple selection loop. We chose the process with the highest
@@ -613,7 +632,8 @@
* OR try to be smart about which process to kill. Note that we
* don't have to be perfect here, we just have to be good.
*/
-void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
+void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
+ int order, nodemask_t *nodemask)
{
unsigned long freed = 0;
enum oom_constraint constraint;
@@ -632,7 +652,7 @@
* Check if there were limitations on the allocation (only relevant for
* NUMA) that may require different handling.
*/
- constraint = constrained_alloc(zonelist, gfp_mask);
+ constraint = constrained_alloc(zonelist, gfp_mask, nodemask);
read_lock(&tasklist_lock);
switch (constraint) {