Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754037Ab3JIGCf (ORCPT ); Wed, 9 Oct 2013 02:02:35 -0400 Received: from mail-ee0-f52.google.com ([74.125.83.52]:37194 "EHLO mail-ee0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751902Ab3JIGCc (ORCPT ); Wed, 9 Oct 2013 02:02:32 -0400 Date: Wed, 9 Oct 2013 08:02:28 +0200 From: Ingo Molnar To: Frederic Weisbecker Cc: Peter Zijlstra , Andi Kleen , Thomas Gleixner , "H. Peter Anvin" , 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: <20131009060228.GB7664@gmail.com> 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> <20131008195556.GD8392@localhost.localdomain> <20131008200521.GE13848@laptop.programming.kicks-ass.net> <20131008203526.GG8392@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131008203526.GG8392@localhost.localdomain> 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: 991 Lines: 27 * Frederic Weisbecker wrote: > On Tue, Oct 08, 2013 at 10:05:21PM +0200, Peter Zijlstra wrote: > > On Tue, Oct 08, 2013 at 09:55:59PM +0200, Frederic Weisbecker wrote: > > > 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. > > > > we used to have this in __switch_to_xtra(), right? > > Right. > > And then it got replaced by perf events scheduling. Which we have anyway - so this moved complexity out the contex switch path, for the common case where no hardware-breakpoints are used. Thanks, Ingo -- 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/