Re: [PATCH] oom: add tracepoints for oom_score_adj
From: KAMEZAWA Hiroyuki
Date: Thu Dec 08 2011 - 18:42:40 EST
On Thu, 08 Dec 2011 12:33:35 -0500
KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
> On 12/7/2011 8:47 PM, KAMEZAWA Hiroyuki wrote:
> > On Wed, 07 Dec 2011 11:52:02 -0500
> > KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
> >
> >> On 12/6/2011 7:54 PM, KAMEZAWA Hiroyuki wrote:
> >>> >From 28189e4622fd97324893a0b234183f64472a54d6 Mon Sep 17 00:00:00 2001
> >>> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> >>> Date: Wed, 7 Dec 2011 09:58:16 +0900
> >>> Subject: [PATCH] oom: trace point for oom_score_adj
> >>>
> >>> oom_score_adj is set to prevent a task from being killed by OOM-Killer.
> >>> Some daemons sets this value and their children inerit it sometimes.
> >>> Because inheritance of oom_score_adj is done automatically, users
> >>> can be confused at seeing the value and finds it's hard to debug.
> >>>
> >>> This patch adds trace point for oom_score_adj. This adds 3 trace
> >>> points. at
> >>> - update oom_score_adj
> >>
> >>
> >>> - fork()
> >>> - rename task->comm(typically, exec())
> >>
> >> I don't think they have oom specific thing. Can you please add generic fork and
> >> task rename tracepoint instead?
> >>
> > I think it makes oom-targeted debug difficult.
> > This tracehook using task->signal->oom_score_adj as filter.
> > This reduces traces much and makes debugging easier.
> >
> > If you need another trace point for other purpose, another trace point
> > should be better. For generic purpose, oom_socre_adj filtering will not
> > be necessary.
>
> see Documentation/trace/event.txt 5. Event filgtering
>
> Now, both ftrace and perf have good filter feature. Isn't this enough?
>
Could you make patch ? Then, I stop this and go other probelm.
Thanks,
-Kame
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