From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19286 invoked by alias); 28 Feb 2013 07:16:59 -0000 Received: (qmail 19181 invoked by uid 22791); 28 Feb 2013 07:16:57 -0000 X-SWARE-Spam-Status: No, hits=-6.6 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,KHOP_SPAMHAUS_DROP,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 28 Feb 2013 07:16:50 +0000 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r1S7GkLR016059 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 28 Feb 2013 02:16:46 -0500 Received: from host2.jankratochvil.net (ovpn-116-19.ams2.redhat.com [10.36.116.19]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id r1S7GftY008598 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Thu, 28 Feb 2013 02:16:44 -0500 Date: Thu, 28 Feb 2013 07:56:00 -0000 From: Jan Kratochvil To: "Metzger, Markus T" Cc: "gdb-patches@sourceware.org" , "markus.t.metzger@gmail.com" Subject: Re: [PATCH 2/3] record-btrace, disas: omit pc prefix Message-ID: <20130228071641.GA22184@host2.jankratochvil.net> References: <1361808917-16934-1-git-send-email-markus.t.metzger@intel.com> <1361808917-16934-3-git-send-email-markus.t.metzger@intel.com> <20130227075925.GA5003@host2.jankratochvil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-IsSubscribed: yes 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 X-SW-Source: 2013-02/txt/msg00725.txt.bz2 On Thu, 28 Feb 2013 08:03:04 +0100, Metzger, Markus T wrote: > Within a loop, you will see repeating => very frequently. > > (gdb) rec inst - > 0x00000000004006ec <_ZL4loopPv+8>: mov 0x200955(%rip),%rax # 0x601048 <_ZL6shared> > => 0x00000000004006f3 <_ZL4loopPv+15>: add $0x1,%rax > 0x00000000004006f7 <_ZL4loopPv+19>: mov %rax,0x20094a(%rip) # 0x601048 <_ZL6shared> > 0x00000000004006fe <_ZL4loopPv+26>: jmp 0x4006ec <_ZL4loopPv+8> > 0x00000000004006ec <_ZL4loopPv+8>: mov 0x200955(%rip),%rax # 0x601048 <_ZL6shared> > => 0x00000000004006f3 <_ZL4loopPv+15>: add $0x1,%rax > 0x00000000004006f7 <_ZL4loopPv+19>: mov %rax,0x20094a(%rip) # 0x601048 <_ZL6shared> > 0x00000000004006fe <_ZL4loopPv+26>: jmp 0x4006ec <_ZL4loopPv+8> > 0x00000000004006ec <_ZL4loopPv+8>: mov 0x200955(%rip),%rax # 0x601048 <_ZL6shared> > => 0x00000000004006f3 <_ZL4loopPv+15>: add $0x1,%rax > (gdb) I did not think about this case but I still find it correct, => should display the current PC and it is the current PC. > > (gdb) record instruction-history > > warning: Recorded trace may be corrupted. > > warning: Recorded trace may be corrupted. > > warning: Recorded trace may be corrupted. > > That's unexpected. If you can reproduce this, would you please send > me the reproducer so I can have a look at it? I have patched intel_supports_btrace on my model 0x1a, couldn't it be the reason? Jan