From: David Rientjes <rientjes@xxxxxxxxxx> Subject: mm, oom: dump stack of victim when reaping failed When a process cannot be oom reaped, for whatever reason, currently the list of locks that are held is currently dumped to the kernel log. Much more interesting is the stack trace of the victim that cannot be reaped. If the stack trace is dumped, we have the ability to find related occurrences in the same kernel code and hopefully solve the issue that is making it wedged. Dump the stack trace when a process fails to be oom reaped. Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2001141519280.200484@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/oom_kill.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/oom_kill.c~mm-oom-dump-stack-of-victim-when-reaping-failed +++ a/mm/oom_kill.c @@ -26,6 +26,7 @@ #include <linux/sched/mm.h> #include <linux/sched/coredump.h> #include <linux/sched/task.h> +#include <linux/sched/debug.h> #include <linux/swap.h> #include <linux/timex.h> #include <linux/jiffies.h> @@ -620,6 +621,7 @@ static void oom_reap_task(struct task_st pr_info("oom_reaper: unable to reap pid:%d (%s)\n", task_pid_nr(tsk), tsk->comm); + sched_show_task(tsk); debug_show_all_locks(); done: _
