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Date: Fri, 8 Apr 2011 22:38:29 +0200
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: David Sharp <dhsharp@google.com>,
        Vaibhav Nagarnaik <vnagarnaik@google.com>,
        Paul Menage <menage@google.com>, Li Zefan <lizf@cn.fujitsu.com>,
        Stephane Eranian <eranian@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michael Rubin <mrubin@google.com>, Ken Chen <kenchen@google.com>,
        linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: [RFC] tracing: Adding cgroup aware tracing functionality
Message-ID: <20110408203827.GA26667@nowhere>
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On Fri, Apr 08, 2011 at 09:00:56PM +0200, Frederic Weisbecker wrote:
> On Fri, Apr 08, 2011 at 03:37:48AM -0400, Steven Rostedt wrote:
> > I actually agree, as perf is more focused on per process (or group) than
> > ftrace. But that said, I guess the issue is also, if they have a simple
> > solution that is not invasive and suits their needs, what's the harm in
> > accepting it?
> 
> What about a kind of cgroup_of(path) operator that we can use on
> filters?
> 
> 	common_pid cgroup_of(path)
> or
> 	common_pid __cgroup_of__ path
> 
> That way you don't bloat the tracing fast path?

Note in this example, we would simply ignore the common_pid
value and assume that pid is the one of current. This economizes
a step to pid -> task resolution.
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