Date: Fri, 18 May 2012 13:59:57 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@amd64.org>, Frederic Weisbecker <fweisbec@gmail.com>,
        Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Borislav Petkov <borislav.petkov@amd.com>
Subject: Re: [PATCH 1/2] perf: Add persistent event facilities
Message-ID: <20120518115957.GB19785@gmail.com>
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* Peter Zijlstra <peterz@infradead.org> wrote:

> On Fri, 2012-05-18 at 13:03 +0200, Borislav Petkov wrote:
> > >  - you allow an arbitrary place in debugfs; this might make finding
> > > them 'interesting'. Should we put them all in the same place?
> > 
> > My take on this is that we want to be able to make the same events we
> > have now, persistent. Basically not trace for the duration of a child
> > process but in a process-agnostic way, system-wide.
> 
> This would argue against per-task persistent events.. 

Yeah, 'persistency' is something that's per CPU at minimum.

> Note the plural there, it might be very desirable to allow 
> multiple events into a single persistent buffer.

very, very, very much so. One (per CPU) buffer, with many events 
multiplexed into it.

Thanks,

	Ingo
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