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Date: Wed, 18 Nov 2009 01:18:19 +0100
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
       Li Zefan <lizf@cn.fujitsu.com>, Prasad <prasad@linux.vnet.ibm.com>,
       Alan Stern <stern@rowland.harvard.edu>,
       Arnaldo Carvalho de Melo <acme@redhat.com>,
       Steven Rostedt <rostedt@goodmis.org>, Jan Kiszka <jan.kiszka@web.de>,
       Jiri Slaby <jirislaby@gmail.com>, Avi Kivity <avi@redhat.com>,
       Paul Mackerras <paulus@samba.org>, Mike Galbraith <efault@gmx.de>,
       Masami Hiramatsu <mhiramat@redhat.com>,
       Paul Mundt <lethal@linux-sh.org>,
       Arjan van de Ven <arjan@linux.intel.com>
Subject: Re: [PATCH 3/7 v6] perf/core: Add a callback to perf events
Message-ID: <20091118001815.GA8187@nowhere>
References: <1257694141-5670-1-git-send-email-fweisbec@gmail.com> <1257694141-5670-4-git-send-email-fweisbec@gmail.com> <1258457333.7816.186.camel@laptop>
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On Tue, Nov 17, 2009 at 12:28:53PM +0100, Peter Zijlstra wrote:
> On Sun, 2009-11-08 at 16:28 +0100, Frederic Weisbecker wrote:
> > A simple callback in a perf event can be used for multiple purposes.
> > For example it is useful for triggered based events like hardware
> > breakpoints that need a callback to dispatch a triggered breakpoint
> > event.
> > 
> > v2: Simplify a bit the callback attribution as suggested by Paul
> >     Mackerras
> 
> Yuck! So we add an opaque callback without semantics nor usage.


Yeah, this is intended for events that need to be able to trigger
events to different channels. In the case of hw-breakpoints, it's
either perf buffer, ptrace, etc...

Should I add some comments about it?

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