Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755530Ab3JHT4J (ORCPT ); Tue, 8 Oct 2013 15:56:09 -0400 Received: from mail-wg0-f52.google.com ([74.125.82.52]:54873 "EHLO mail-wg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752516Ab3JHT4F (ORCPT ); Tue, 8 Oct 2013 15:56:05 -0400 Date: Tue, 8 Oct 2013 21:55:59 +0200 From: Frederic Weisbecker To: Andi Kleen , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Andi Kleen Subject: Re: [PATCH 6/6] x86: Allow disabling HW_BREAKPOINTS and PERF_EVENTS Message-ID: <20131008195556.GD8392@localhost.localdomain> References: <1380922788-23112-1-git-send-email-andi@firstfloor.org> <1380922788-23112-7-git-send-email-andi@firstfloor.org> <20131005070806.GA16922@gmail.com> <20131005170552.GI6882@two.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131005170552.GI6882@two.firstfloor.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1270 Lines: 36 On Sat, Oct 05, 2013 at 07:05:52PM +0200, Andi Kleen wrote: > On Sat, Oct 05, 2013 at 09:08:06AM +0200, Ingo Molnar wrote: > > > > * Andi Kleen wrote: > > > > > From: Andi Kleen > > > > > > As suggested by Ingo. > > > > No, you haven't read my suggestion carefully enough so NAK. > > Ok I trust you will do a better solution then to save the 700+k text. > Ball is in your court. Ok I have two choices in mind. 1) make breakpoints independant from perf. The drawback is that we must then add seperate hooks on context switch for ptrace breakpoints. OTOH we get rid of the perf -> breakpoint -> perf circular dependency, which is the very controversial thing. 2) Build breakpoints conditionally (depend on CONFIG_EXPERT). hpa didn't like much that solution because breakpoints is an elementary debugging feature that is too useful to be unbuild. Both ways can allow us to disable perf on x86. We just need to agree on a solution and I'll happily work on it. Ingo, others? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/