In dump_oom_summary() oc->constraint is used to show
oom_constraint_text, but it hasn't been set before.
So the value of it is always the default value 0.
We should set it in constrained_alloc().
Bellow is the output when memcg oom occurs,
before this patch:
[ 133.078102] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),
cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=7997,uid=0
after this patch:
[ 952.977946] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),
cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=13681,uid=0
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
mm/oom_kill.c | 35 +++++++++++++++++++++++++----------
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 5a58778..075e5cf 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -261,29 +261,37 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)
struct zone *zone;
struct zoneref *z;
enum zone_type high_zoneidx = gfp_zone(oc->gfp_mask);
+ enum oom_constraint constraint;
bool cpuset_limited = false;
int nid;
if (is_memcg_oom(oc)) {
oc->totalpages = mem_cgroup_get_max(oc->memcg) ?: 1;
- return CONSTRAINT_MEMCG;
+ constraint = CONSTRAINT_MEMCG;
+ goto out;
}
/* Default to all available memory */
oc->totalpages = totalram_pages() + total_swap_pages;
- if (!IS_ENABLED(CONFIG_NUMA))
- return CONSTRAINT_NONE;
+ if (!IS_ENABLED(CONFIG_NUMA)) {
+ constraint = CONSTRAINT_NONE;
+ goto out;
+ }
- if (!oc->zonelist)
- return CONSTRAINT_NONE;
+ if (!oc->zonelist) {
+ constraint = CONSTRAINT_NONE;
+ goto out;
+ }
/*
* 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 (oc->gfp_mask & __GFP_THISNODE)
- return CONSTRAINT_NONE;
+ if (oc->gfp_mask & __GFP_THISNODE) {
+ constraint = CONSTRAINT_NONE;
+ goto out;
+ }
/*
* This is not a __GFP_THISNODE allocation, so a truncated nodemask in
@@ -295,7 +303,8 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)
oc->totalpages = total_swap_pages;
for_each_node_mask(nid, *oc->nodemask)
oc->totalpages += node_spanned_pages(nid);
- return CONSTRAINT_MEMORY_POLICY;
+ constraint = CONSTRAINT_MEMORY_POLICY;
+ goto out;
}
/* Check this allocation failure is caused by cpuset's wall function */
@@ -308,9 +317,15 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)
oc->totalpages = total_swap_pages;
for_each_node_mask(nid, cpuset_current_mems_allowed)
oc->totalpages += node_spanned_pages(nid);
- return CONSTRAINT_CPUSET;
+ constraint = CONSTRAINT_CPUSET;
+ goto out;
}
- return CONSTRAINT_NONE;
+
+ constraint = CONSTRAINT_NONE;
+
+out:
+ oc->constraint = constraint;
+ return constraint;
}
static int oom_evaluate_task(struct task_struct *task, void *arg)
--
1.8.3.1
