Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756329AbZFJNe7 (ORCPT ); Wed, 10 Jun 2009 09:34:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752867AbZFJNew (ORCPT ); Wed, 10 Jun 2009 09:34:52 -0400 Received: from mga01.intel.com ([192.55.52.88]:7483 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752394AbZFJNev convert rfc822-to-8bit (ORCPT ); Wed, 10 Jun 2009 09:34:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.41,341,1241420400"; d="scan'208";a="698136335" From: "Metzger, Markus T" To: Peter Zijlstra CC: Ingo Molnar , "mingo@redhat.com" , "hpa@zytor.com" , "linux-kernel@vger.kernel.org" , "tglx@linutronix.de" , "oleg@redhat.com" , "linux-tip-commits@vger.kernel.org" Date: Wed, 10 Jun 2009 14:32:05 +0100 Subject: RE: [tip:tracing/core] x86, bts: reenable ptrace branch trace support Thread-Topic: [tip:tracing/core] x86, bts: reenable ptrace branch trace support Thread-Index: Acnpz4N9aPFGWHo+RB6S5Q5FqIcfkQAAA2Vg Message-ID: <928CFBE8E7CB0040959E56B4EA41A77EBBC651F4@irsmsx504.ger.corp.intel.com> References: <20090424094448.A30216@sedona.ch.intel.com> <1244637843.13761.11786.camel@twins> <20090610125108.GA13506@elte.hu> <928CFBE8E7CB0040959E56B4EA41A77EBBC651E2@irsmsx504.ger.corp.intel.com> <1244640558.13761.11833.camel@twins> In-Reply-To: <1244640558.13761.11833.camel@twins> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2074 Lines: 52 >-----Original Message----- >From: Peter Zijlstra [mailto:peterz@infradead.org] >Sent: Wednesday, June 10, 2009 3:29 PM >To: Metzger, Markus T >Cc: Ingo Molnar; mingo@redhat.com; hpa@zytor.com; linux-kernel@vger.kernel.org; tglx@linutronix.de; >oleg@redhat.com; linux-tip-commits@vger.kernel.org >Subject: RE: [tip:tracing/core] x86, bts: reenable ptrace branch trace support > >On Wed, 2009-06-10 at 14:22 +0100, Metzger, Markus T wrote: >> >> The Debug Store interface is completely in-kernel. It does not expose >> anything to the outside world. >> >> What we expose is a ptrace interface for branch tracing. >> That this is built on top of Debug Store is completely hidden. >> The Debug Store interface may be changed without impacting the >> user-visible part at any time. >> >> I do think that a ptrace interface makes sense since debuggers are the >> targeted users for branch tracing. >> >> I don't see why we should not merge the fixes now and then rework the >> in-kernel parts as needed for supporting PEBS. > >Ok, so what is all that account_locked_memory() for? To allow debuggers (users) to decide how much memory they want to spend on branch tracing. regards, markus. --------------------------------------------------------------------- Intel GmbH Dornacher Strasse 1 85622 Feldkirchen/Muenchen Germany Sitz der Gesellschaft: Feldkirchen bei Muenchen Geschaeftsfuehrer: Douglas Lusk, Peter Gleissner, Hannes Schwaderer Registergericht: Muenchen HRB 47456 Ust.-IdNr. VAT Registration No.: DE129385895 Citibank Frankfurt (BLZ 502 109 00) 600119052 This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. -- 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/