Lowering memory.max can trigger an oom-kill if the reclaim does not
succeed. However if oom-killer does not find a process for killing, it
dumps a lot of warnings.
Deleting a memcg does not reclaim memory from it and the memory can
linger till there is a memory pressure. One normal way to proactively
reclaim such memory is to set memory.max to 0 just before deleting the
memcg. However if some of the memcg's memory is pinned by others, this
operation can trigger an oom-kill without any process and thus can log a
lot un-needed warnings. So, ignore all such warnings from memory.max.
Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
---
include/linux/oom.h | 3 +++
mm/memcontrol.c | 9 +++++----
mm/oom_kill.c | 2 +-
3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/include/linux/oom.h b/include/linux/oom.h
index c696c265f019..6345dc55df64 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -52,6 +52,9 @@ struct oom_control {
/* Used to print the constraint info. */
enum oom_constraint constraint;
+
+ /* Do not warn even if there is no process to be killed. */
+ bool no_warn;
};
extern struct mutex oom_lock;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 317dbbaac603..a1f00d9b9bb0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1571,7 +1571,7 @@ unsigned long mem_cgroup_size(struct mem_cgroup *memcg)
}
static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
- int order)
+ int order, bool no_warn)
{
struct oom_control oc = {
.zonelist = NULL,
@@ -1579,6 +1579,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
.memcg = memcg,
.gfp_mask = gfp_mask,
.order = order,
+ .no_warn = no_warn,
};
bool ret;
@@ -1821,7 +1822,7 @@ static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int
mem_cgroup_oom_notify(memcg);
mem_cgroup_unmark_under_oom(memcg);
- if (mem_cgroup_out_of_memory(memcg, mask, order))
+ if (mem_cgroup_out_of_memory(memcg, mask, order, false))
ret = OOM_SUCCESS;
else
ret = OOM_FAILED;
@@ -1880,7 +1881,7 @@ bool mem_cgroup_oom_synchronize(bool handle)
mem_cgroup_unmark_under_oom(memcg);
finish_wait(&memcg_oom_waitq, &owait.wait);
mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask,
- current->memcg_oom_order);
+ current->memcg_oom_order, false);
} else {
schedule();
mem_cgroup_unmark_under_oom(memcg);
@@ -6106,7 +6107,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of,
}
memcg_memory_event(memcg, MEMCG_OOM);
- if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0))
+ if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0, true))
break;
}
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 463b3d74a64a..5ace39f6fe1e 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -1098,7 +1098,7 @@ bool out_of_memory(struct oom_control *oc)
select_bad_process(oc);
/* Found nothing?!?! */
- if (!oc->chosen) {
+ if (!oc->chosen && !oc->no_warn) {
dump_header(oc, NULL);
pr_warn("Out of memory and no killable processes...\n");
/*
--
2.26.2.526.g744177e7f7-goog
