Re: [-mm patch] Show memcg information during OOM

Balbir Singh
2009-02-02T14:08:58Z

* Balbir Singh <balbir@linux.vnet.ibm.com> [2009-02-02 18:22:40]:

> Hi, All,
>
> I found the following patch useful while debugging the memory
> controller. It adds additional information if memcg invoked the OOM.
>
> Comments, Suggestions?
>

Description: Add RSS and swap to OOM output from memcg

From: Balbir Singh <balbir@linux.vnet.ibm.com>

This patch displays memcg values like failcnt, usage and limit
when an OOM occurs due to memcg.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

include/linux/memcontrol.h | 5 +++++
mm/memcontrol.c | 16 ++++++++++++++++
mm/oom_kill.c | 1 +
3 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 326f45c..2ce1737 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -104,6 +104,7 @@ struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
struct zone *zone);
struct zone_reclaim_stat*
mem_cgroup_get_reclaim_stat_from_page(struct page *page);
+extern void mem_cgroup_print_mem_info(struct mem_cgroup *memcg);

#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
extern int do_swap_account;
@@ -270,6 +271,10 @@ mem_cgroup_get_reclaim_stat_from_page(struct page *page)
return NULL;
}

+void mem_cgroup_print_mem_info(struct mem_cgroup *memcg)
+{
+}
+
#endif /* CONFIG_CGROUP_MEM_CONT */

#endif /* _LINUX_MEMCONTROL_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8e4be9c..d134a1d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -813,6 +813,22 @@ bool mem_cgroup_oom_called(struct task_struct *task)
rcu_read_unlock();
return ret;
}
+
+void mem_cgroup_print_mem_info(struct mem_cgroup *memcg)
+{
+ printk(KERN_WARNING "Memory cgroups's name %s\n",
+ memcg->css.cgroup->dentry->d_name.name);
+ printk(KERN_WARNING "Memory cgroup RSS : usage %llu, limit %llu"
+ " failcnt %llu\n", res_counter_read_u64(&memcg->res, RES_USAGE),
+ res_counter_read_u64(&memcg->res, RES_LIMIT),
+ res_counter_read_u64(&memcg->res, RES_FAILCNT));
+ printk(KERN_WARNING "Memory cgroup swap: usage %llu, limit %llu "
+ "failcnt %llu\n",
+ res_counter_read_u64(&memcg->memsw, RES_USAGE),
+ res_counter_read_u64(&memcg->memsw, RES_LIMIT),
+ res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
+}
+
/*
* Unlike exported interface, "oom" parameter is added. if oom==true,
* oom-killer can be invoked.
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index d3b9bac..b8e53ae 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -392,6 +392,7 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
current->comm, gfp_mask, order, current->oomkilladj);
task_lock(current);
cpuset_print_task_mems_allowed(current);
+ mem_cgroup_print_mem_info(mem);
task_unlock(current);
dump_stack();
show_mem();

--
Balbir