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From: Peter Zijlstra <peterz@infradead.org>
To: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: ast@fb.com, lkml <linux-kernel@vger.kernel.org>,
	acme@kernel.org, alexander.shishkin@linux.intel.com,
	mingo@redhat.com, daniel@iogearbox.net, rostedt@goodmis.org,
	Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
	ebiederm@xmission.com, sargun@sargun.me,
	Aravinda Prasad <aravinda@linux.vnet.ibm.com>,
	brendan.d.gregg@gmail.com
Subject: Re: [PATCH v2 1/2] perf: add container identifier entry in perf sample data
Date: Fri, 2 Sep 2016 15:59:36 +0200	[thread overview]
Message-ID: <20160902135936.GH10153@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <58edcf4e-80d4-3b0e-773d-29d28070392d@linux.vnet.ibm.com>

On Fri, Sep 02, 2016 at 07:25:31PM +0530, Hari Bathini wrote:
> >I'm thinking this value is mostly the same for tasks, just like COMM and
> 
> I think so, too. Namespaces aren't changed that often for tasks...
> 
> >MMAP. Could we therefore not emit (sideband) events whenever a task
> >changes namespace and get the same information but with tons less data?
> 
> You mean, something like PERF_RECORD_NAMESPACE that
> emits events on fork, clone, setns..?

Yep.

> 
> >That also gives the possibility of recording all namespaces, not just
> >the one.
> 
> True. If we record all namespaces, container identifier interpretation
> can be left to the userspace to decide, which is much more flexible...

The only complication is initial state, on record start you'd have to
trawl /proc and generate 'fake' namespace records for all (relevant)
tasks.

We do the same with MMAP records, we parse /proc/$pid/maps for that.

Is this namespace stuff available in /proc somewhere?

  reply	other threads:[~2016-09-02 13:59 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-30 16:27 [PATCH v2 1/2] perf: add container identifier entry in perf sample data Hari Bathini
2016-08-30 16:27 ` [PATCH v2 2/2] perf tool: add container identifier entry related changes Hari Bathini
2016-09-01  9:09 ` [PATCH v2 1/2] perf: add container identifier entry in perf sample data Peter Zijlstra
2016-09-02 13:55   ` Hari Bathini
2016-09-02 13:59     ` Peter Zijlstra [this message]
2016-09-02 16:55       ` Hari Bathini

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