diff mbox series

mm/oom: Add killed process selection information

Message ID 20190815060604.3675-1-echron@arista.com (mailing list archive)
State New, archived
Headers show
Series mm/oom: Add killed process selection information | expand

Commit Message

Edward Chron Aug. 15, 2019, 6:06 a.m. UTC
For an OOM event: print oom_score_adj value for the OOM Killed process
to document what the oom score adjust value was at the time the process
at the time of the OOM event. The value can be set by the user and it
effects the resulting oom_score so useful to document this value.

Sample message output:
Aug 14 23:00:02 testserver kernel: Out of memory: Killed process 2692
 (oomprocs) total-vm:1056800kB, anon-rss:1052760kB, file-rss:4kB,i
 shmem-rss:0kB oom_score_adj:1000

Signed-off-by: Edward Chron <echron@arista.com>
---
 mm/oom_kill.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

Michal Hocko Aug. 15, 2019, 8:24 a.m. UTC | #1
On Wed 14-08-19 23:06:04, Edward Chron wrote:
> For an OOM event: print oom_score_adj value for the OOM Killed process
> to document what the oom score adjust value was at the time the process
> at the time of the OOM event. The value can be set by the user and it
> effects the resulting oom_score so useful to document this value.

This value is interesting especially for setups which do not print
eligible tasks (sysctl oom_dump_tasks = 0) and helps to notice a
misconfiguration <YOUR UDEV EXAMPLE GOES HERE> or to confirm that
oom_score_adj configuration applies as expected.
 
> Sample message output:
> Aug 14 23:00:02 testserver kernel: Out of memory: Killed process 2692
>  (oomprocs) total-vm:1056800kB, anon-rss:1052760kB, file-rss:4kB,i
>  shmem-rss:0kB oom_score_adj:1000
> 
> Signed-off-by: Edward Chron <echron@arista.com>

With that feel free to add
Acked-by: Michal Hocko <mhocko@suse.com>

and post as a stand alone patch. Btw. the patch could be simplified by
not using a helper variable and using victim->signal->oom_score_adj
right in the pr_err.

Thanks!

> ---
>  mm/oom_kill.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index eda2e2a0bdc6..6b1674cac377 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -858,6 +858,7 @@ static void __oom_kill_process(struct task_struct *victim, const char *message)
>  	struct task_struct *p;
>  	struct mm_struct *mm;
>  	bool can_oom_reap = true;
> +	long adj;
>  
>  	p = find_lock_task_mm(victim);
>  	if (!p) {
> @@ -877,6 +878,8 @@ static void __oom_kill_process(struct task_struct *victim, const char *message)
>  	count_vm_event(OOM_KILL);
>  	memcg_memory_event_mm(mm, MEMCG_OOM_KILL);
>  
> +	adj = (long)victim->signal->oom_score_adj;
> +
>  	/*
>  	 * We should send SIGKILL before granting access to memory reserves
>  	 * in order to prevent the OOM victim from depleting the memory
> @@ -884,12 +887,12 @@ static void __oom_kill_process(struct task_struct *victim, const char *message)
>  	 */
>  	do_send_sig_info(SIGKILL, SEND_SIG_PRIV, victim, PIDTYPE_TGID);
>  	mark_oom_victim(victim);
> -	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
> +	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB oom_score_adj:%ld\n",
>  		message, task_pid_nr(victim), victim->comm,
>  		K(victim->mm->total_vm),
>  		K(get_mm_counter(victim->mm, MM_ANONPAGES)),
>  		K(get_mm_counter(victim->mm, MM_FILEPAGES)),
> -		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)));
> +		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)), adj);
>  	task_unlock(victim);
>  
>  	/*
> -- 
> 2.20.1
diff mbox series

Patch

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index eda2e2a0bdc6..6b1674cac377 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -858,6 +858,7 @@  static void __oom_kill_process(struct task_struct *victim, const char *message)
 	struct task_struct *p;
 	struct mm_struct *mm;
 	bool can_oom_reap = true;
+	long adj;
 
 	p = find_lock_task_mm(victim);
 	if (!p) {
@@ -877,6 +878,8 @@  static void __oom_kill_process(struct task_struct *victim, const char *message)
 	count_vm_event(OOM_KILL);
 	memcg_memory_event_mm(mm, MEMCG_OOM_KILL);
 
+	adj = (long)victim->signal->oom_score_adj;
+
 	/*
 	 * We should send SIGKILL before granting access to memory reserves
 	 * in order to prevent the OOM victim from depleting the memory
@@ -884,12 +887,12 @@  static void __oom_kill_process(struct task_struct *victim, const char *message)
 	 */
 	do_send_sig_info(SIGKILL, SEND_SIG_PRIV, victim, PIDTYPE_TGID);
 	mark_oom_victim(victim);
-	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
+	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB oom_score_adj:%ld\n",
 		message, task_pid_nr(victim), victim->comm,
 		K(victim->mm->total_vm),
 		K(get_mm_counter(victim->mm, MM_ANONPAGES)),
 		K(get_mm_counter(victim->mm, MM_FILEPAGES)),
-		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)));
+		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)), adj);
 	task_unlock(victim);
 
 	/*