From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: perf: prctl(PR_TASK_PERF_EVENTS_DISABLE) has no effect Date: Tue, 31 Jul 2012 09:16:00 +0200 Message-ID: <20120731071600.GB2950@gmail.com> References: <501121D3.3060700@mentor.com> <20120727072647.GA3965@gmail.com> <1343376002.32120.22.camel@twins> <20120727081830.GA4258@gmail.com> <1343377764.32120.29.camel@twins> <20120727115351.GA4514@gmail.com> <1343713645.20897.11.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-we0-f174.google.com ([74.125.82.174]:58974 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751217Ab2GaHQJ (ORCPT ); Tue, 31 Jul 2012 03:16:09 -0400 Received: by weyx8 with SMTP id x8so4123535wey.19 for ; Tue, 31 Jul 2012 00:16:08 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1343713645.20897.11.camel@twins> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: Iegorov Oleg , linux-perf-users@vger.kernel.org, mingo@elte.hu, acme@ghostprotocols.net, =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Arnaldo Carvalho de Melo , Thomas Gleixner * Peter Zijlstra wrote: > 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. We could add a new prctl if you think, but I thought to not complicate it and offer it as a simple extension of the semantics to loop over active events. No existing binary's behavior will change. Thanks, Ingo