Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752472AbZGWT4L (ORCPT ); Thu, 23 Jul 2009 15:56:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751782AbZGWT4K (ORCPT ); Thu, 23 Jul 2009 15:56:10 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:54161 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751658AbZGWT4J (ORCPT ); Thu, 23 Jul 2009 15:56:09 -0400 Date: Thu, 23 Jul 2009 15:56:08 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Peter Zijlstra cc: Frederic Weisbecker , 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" Subject: Re: [RFC][PATCH 5/5] perfcounter: Add support for kernel hardware breakpoints In-Reply-To: <1248371110.4681.1.camel@laptop> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 804 Lines: 22 On Thu, 23 Jul 2009, Peter Zijlstra wrote: > > Is there a limit to these hardware breakpoints? If so, the software Certainly there's a limit. They require hardware resources, after all. > > 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? On x86, hardware breakpoints take virtual addresses. I don't know about other architectures. Alan Stern -- 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/