From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 101031 invoked by alias); 16 Sep 2015 12:54:22 -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 101017 invoked by uid 89); 16 Sep 2015 12:54:21 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Wed, 16 Sep 2015 12:54:20 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id A97EC461C1; Wed, 16 Sep 2015 12:54:19 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t8GCsHb7012034; Wed, 16 Sep 2015 08:54:18 -0400 Message-ID: <55F96679.7070503@redhat.com> Date: Wed, 16 Sep 2015 12:54:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: "Metzger, Markus T" , Eli Zaretskii CC: "gdb-patches@sourceware.org" Subject: Re: [PATCH v2 17/17] infrun: scheduler-locking reverse References: <1441954298-25298-1-git-send-email-markus.t.metzger@intel.com> <1441954298-25298-18-git-send-email-markus.t.metzger@intel.com> <83io7h4eze.fsf@gnu.org> <55F2970D.6040603@redhat.com> <838u8d49d3.fsf@gnu.org> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-09/txt/msg00371.txt.bz2 On 09/16/2015 01:27 PM, Metzger, Markus T wrote: >> -----Original Message----- >> From: Eli Zaretskii [mailto:eliz@gnu.org] >> Sent: Friday, September 11, 2015 11:02 AM >> To: Pedro Alves >> Cc: Metzger, Markus T; gdb-patches@sourceware.org >> Subject: Re: [PATCH v2 17/17] infrun: scheduler-locking reverse >> >>> Date: Fri, 11 Sep 2015 09:55:41 +0100 >>> From: Pedro Alves >>> CC: gdb-patches@sourceware.org > > The second paragraph of [1] says "When this [record] target is in use, if the > execution log includes the record for the next instruction, gdb will debug in > replay mode.". > > Following this definition of "replay mode", I agree with Eli's first suggestion > to call the new scheduler-locking mode "replay". Me too. > It looks like "replay" mode means that GDB is executing from its (own) > execution log; "record" mode means that GDB is extending its execution > log. That makes sense. > > Traditionally, GDB records when stepping forward from the end of the > execution log. On targets that support native reverse-stepping, however, > GDB is able to extend its execution log also when stepping backward from > the beginning of GDB's execution log. Sounds like wishful thinking on the part of the author though then. I don't think that gdb actually implements that, or ever did. > This doesn't work with record btrace. AFAICS, it doesn't work with record-full either. When you reach the end of the execution log going backwards, and then issue another back-step, record_full_wait_1 does not try to step backwards any further, but just immediately returns TARGET_WAITKIND_NO_HISTORY again. Thanks, Pedro Alves