From: Yeoreum Yun <yeoreum.yun@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Leo Yan <leo.yan@arm.com>,
mingo@redhat.com, mingo@kernel.org, acme@kernel.org,
namhyung@kernel.org, mark.rutland@arm.com,
alexander.shishkin@linux.intel.com, jolsa@kernel.org,
irogers@google.com, adrian.hunter@intel.com,
kan.liang@linux.intel.com, linux-perf-users@vger.kernel.org,
linux-kernel@vger.kernel.org, David Wang <00107082@163.com>
Subject: Re: [PATCH 1/1] perf/core: fix dangling cgroup pointer in cpuctx
Date: Wed, 4 Jun 2025 13:54:34 +0100 [thread overview]
Message-ID: <aEBCCvKKS1OLP1Z0@e129823.arm.com> (raw)
In-Reply-To: <20250604123725.GJ38114@noisy.programming.kicks-ass.net>
[...]
> > But suppose the child_task(2) try to fork (child_task3) and
> > inherit the event (create child_event(3, parent_event:0),
> > and at the fork, forking can observe the parent event state as "EXIT".
> > In thie situation why child_event(3, parent_event:0) should be created for
> > child_task(3)?
>
> Yes. You set out to monitor the whole hierarchy, so any child created
> after the first task should be monitored, until such time that you close
> the event.
>
> Notably, a fair number of daemons go about their business by explicitly
> closing their original task in order to detach from the tty.
>
> Also, per the context switch optimization the original event doesn't
> need to stay with the original parent, it can end up on a random child.
Ahh I overlooked daemon case. Thanks for clarification..!
--
Sincerely,
Yeoreum Yun
next prev parent reply other threads:[~2025-06-04 12:55 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-02 18:40 [PATCH 1/1] perf/core: fix dangling cgroup pointer in cpuctx Yeoreum Yun
2025-06-03 2:01 ` David Wang
2025-06-03 4:46 ` [PATCH " Yeoreum Yun
2025-06-03 5:44 ` David Wang
2025-06-03 6:34 ` Yeoreum Yun
2025-06-03 6:39 ` Yeoreum Yun
2025-06-03 6:47 ` David Wang
2025-06-03 6:42 ` David Wang
2025-06-03 7:16 ` Yeoreum Yun
2025-06-03 7:31 ` David Wang
2025-06-03 8:15 ` David Wang
2025-06-03 6:54 ` David Wang
2025-06-03 9:20 ` Yeoreum Yun
2025-06-03 10:08 ` David Wang
2025-06-03 13:41 ` Yeoreum Yun
2025-06-03 14:02 ` David Wang
2025-06-03 14:00 ` Leo Yan
2025-06-03 14:44 ` Peter Zijlstra
2025-06-03 15:17 ` Yeoreum Yun
2025-06-04 7:06 ` Peter Zijlstra
2025-06-04 8:03 ` Peter Zijlstra
2025-06-04 10:06 ` Yeoreum Yun
2025-06-04 12:37 ` Peter Zijlstra
2025-06-04 12:54 ` Yeoreum Yun [this message]
2025-06-04 10:18 ` Leo Yan
2025-06-04 13:58 ` Peter Zijlstra
2025-06-04 15:17 ` Leo Yan
2025-06-04 14:16 ` Peter Zijlstra
2025-06-04 15:46 ` Leo Yan
2025-06-04 15:59 ` Peter Zijlstra
2025-06-05 11:29 ` Peter Zijlstra
2025-06-05 12:33 ` Peter Zijlstra
2025-06-05 17:21 ` Leo Yan
2025-06-05 11:41 ` Peter Zijlstra
2025-06-03 15:05 ` Yeoreum Yun
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