From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19387 invoked by alias); 6 Nov 2013 13:50:15 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 19368 invoked by uid 89); 6 Nov 2013 13:50:15 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_50,RDNS_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no version=3.3.2 X-HELO: mga09.intel.com Received: from Unknown (HELO mga09.intel.com) (134.134.136.24) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 06 Nov 2013 13:48:46 +0000 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 06 Nov 2013 05:45:04 -0800 X-ExtLoop1: 1 Received: from irsmsx104.ger.corp.intel.com ([163.33.3.159]) by orsmga002.jf.intel.com with ESMTP; 06 Nov 2013 05:48:31 -0800 Received: from irsmsx105.ger.corp.intel.com (163.33.3.28) by IRSMSX104.ger.corp.intel.com (163.33.3.159) with Microsoft SMTP Server (TLS) id 14.3.123.3; Wed, 6 Nov 2013 13:48:30 +0000 Received: from irsmsx104.ger.corp.intel.com ([169.254.5.89]) by IRSMSX105.ger.corp.intel.com ([169.254.7.75]) with mapi id 14.03.0123.003; Wed, 6 Nov 2013 13:48:30 +0000 From: "Metzger, Markus T" To: Jan Kratochvil CC: "gdb-patches@sourceware.org" Subject: RE: [patch v6 21/21] record-btrace: add (reverse-)stepping support Date: Wed, 06 Nov 2013 15:06:00 -0000 Message-ID: References: <1379676639-31802-1-git-send-email-markus.t.metzger@intel.com> <1379676639-31802-22-git-send-email-markus.t.metzger@intel.com> <20131006195158.GF28020@host2.jankratochvil.net> In-Reply-To: <20131006195158.GF28020@host2.jankratochvil.net> Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes X-SW-Source: 2013-11/txt/msg00121.txt.bz2 > -----Original Message----- > From: gdb-patches-owner@sourceware.org [mailto:gdb-patches- > owner@sourceware.org] On Behalf Of Jan Kratochvil > Sent: Sunday, October 06, 2013 9:52 PM > > @item btrace > > -Hardware-supported instruction recording. This method does not allow > > -replaying and reverse execution. > > +Hardware-supported instruction recording. This method does not record > > +data. It allows limited replay and reverse execution. >=20 > As discussed in > Message-ID: > com> >=20 > the documentation should mention the full history is usually not kept as = the > btrace buffer commonly overflows. Otherwise user may be curious why the > btrace history is always relatively short. I added a sentence to describe this in the documentation. > I would see it worth a comment even in > (gdb) help record btrace > Start branch trace recording. I don't think that this is necessary or helpful. If we start documenting t= he trace size here, we should also say that trace is collected per thread with no correlation between threads and that tracing induces a run-time overhead and that it may also affect thread interleaving which may cause bug symptoms to disappear, and .... Regards, Markus. Intel GmbH Dornacher Strasse 1 85622 Feldkirchen/Muenchen, Deutschland Sitz der Gesellschaft: Feldkirchen bei Muenchen Geschaeftsfuehrer: Christian Lamprechter, Hannes Schwaderer, Douglas Lusk Registergericht: Muenchen HRB 47456 Ust.-IdNr./VAT Registration No.: DE129385895 Citibank Frankfurt a.M. (BLZ 502 109 00) 600119052