Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753660Ab3C0OsR (ORCPT ); Wed, 27 Mar 2013 10:48:17 -0400 Received: from mail-qe0-f45.google.com ([209.85.128.45]:43780 "EHLO mail-qe0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751613Ab3C0OsQ (ORCPT ); Wed, 27 Mar 2013 10:48:16 -0400 MIME-Version: 1.0 In-Reply-To: <20130327143437.GE1092@krava.brq.redhat.com> References: <1359040242-8269-1-git-send-email-eranian@google.com> <1359040242-8269-12-git-send-email-eranian@google.com> <20130327141425.GC1092@krava.brq.redhat.com> <1364394014.5053.76.camel@laptop> <20130327143437.GE1092@krava.brq.redhat.com> Date: Wed, 27 Mar 2013 15:48:15 +0100 Message-ID: Subject: Re: [PATCH v7 11/18] perf tools: add mem access sampling core support From: Stephane Eranian To: Jiri Olsa Cc: Peter Zijlstra , LKML , "mingo@elte.hu" , "ak@linux.intel.com" , Arnaldo Carvalho de Melo , Namhyung Kim Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1113 Lines: 28 On Wed, Mar 27, 2013 at 3:34 PM, Jiri Olsa wrote: > > On Wed, Mar 27, 2013 at 03:20:14PM +0100, Peter Zijlstra wrote: > > On Wed, 2013-03-27 at 15:14 +0100, Jiri Olsa wrote: > > > we have correct cpumode for sample->ip, but I think it's the > > > PEBS->dla (sample->addr) where we need to guess.. right? > > > > kernel mode very much fakes the cpumode/segment stuff for PEBS. PEBS > > assumes you're running in a linear/flat mode. > > > > say we hit the sample when kernel accesses the user data, we will endup > with IP in kernel space and DATA ptr in user space.. in theory ;-) > Yes, this is possible. So I think we could probably leaverage ip__resolve_ams() and pass the extra parameter for MAP_VARIABLE vs. MAP_FUNCTION. > > and that would need the cpumode guessing for DATA ptr, because > cpumode value is deduced from cs register > > jirka -- 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/