Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753791AbZGWRp4 (ORCPT ); Thu, 23 Jul 2009 13:45:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753424AbZGWRp4 (ORCPT ); Thu, 23 Jul 2009 13:45:56 -0400 Received: from casper.infradead.org ([85.118.1.10]:35100 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752059AbZGWRpz (ORCPT ); Thu, 23 Jul 2009 13:45:55 -0400 Subject: Re: [RFC][PATCH 5/5] perfcounter: Add support for kernel hardware breakpoints From: Peter Zijlstra To: Frederic Weisbecker Cc: Ingo Molnar , LKML , Steven Rostedt , Thomas Gleixner , Mike Galbraith , Paul Mackerras , Arnaldo Carvalho de Melo , Lai Jiangshan , Anton Blanchard , Li Zefan , Zhaolei , KOSAKI Motohiro , Mathieu Desnoyers , "K . Prasad" , Alan Stern In-Reply-To: <1248354493.26273.2.camel@twins> References: <1248109687-7808-1-git-send-email-fweisbec@gmail.com> <1248109687-7808-6-git-send-email-fweisbec@gmail.com> <1248354493.26273.2.camel@twins> Content-Type: text/plain Date: Thu, 23 Jul 2009 19:45:10 +0200 Message-Id: <1248371110.4681.1.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1023 Lines: 23 On Thu, 2009-07-23 at 15:08 +0200, Peter Zijlstra wrote: > On Mon, 2009-07-20 at 13:08 -0400, Frederic Weisbecker wrote: > > This adds the support for kernel hardware breakpoints in perfcounter. > > It is added as a new type of software counter and can be defined by > > using the counter number 5 and by passsing the address of the > > breakpoint to set through the config attribute. > > Is there a limit to these hardware breakpoints? If so, the software > counter model is not sufficient, since we assume we can always schedule > all software counters. However if you were to add more counters than you > have hardware breakpoints you're hosed. Do the breakpoints work on virtual or physical addresses? Also, do we have an 64bit architecture with split address-spaces? -- 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/