From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect
Date: Tue, 31 Jul 2012 07:47:25 +0200
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To: Ingo Molnar <mingo@kernel.org>
Cc: Iegorov Oleg <oleg_iegorov@mentor.com>, linux-perf-users@vger.kernel.org, mingo@elte.hu, acme@ghostprotocols.net, =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <fweisbec@gmail.com>, Arnaldo Carvalho de Melo <acme@infradead.org>, Thomas Gleixner <tglx@linutronix.de>

On Fri, 2012-07-27 at 13:53 +0200, Ingo Molnar wrote:
> > Bloating the interface for something that is already well 
> > possible is.
> 
> There's no 'bloat' worth speaking off: a single bit out of an 
> already allocated bitmap, plus a single check in an already 
> existing loop,

Uhm, no. The existing prctl() loop is over the fd's the task owns, you
want a loop over the fd's that monitor you. This needs new prctl()s at
the very least.