From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60585) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fCMJO-0007KW-Tu for qemu-devel@nongnu.org; Sat, 28 Apr 2018 05:38:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fCMJN-0005Yl-MN for qemu-devel@nongnu.org; Sat, 28 Apr 2018 05:38:34 -0400 Received: from mail-it0-x22c.google.com ([2607:f8b0:4001:c0b::22c]:54805) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fCMJN-0005Ye-Gf for qemu-devel@nongnu.org; Sat, 28 Apr 2018 05:38:33 -0400 Received: by mail-it0-x22c.google.com with SMTP id z6-v6so849300iti.4 for ; Sat, 28 Apr 2018 02:38:33 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <000e01d3ded3$127660d0$37632270$@ru> References: <20180425124533.17182.53165.stgit@pasha-VirtualBox> <000e01d3ded3$127660d0$37632270$@ru> From: Ciro Santilli Date: Sat, 28 Apr 2018 10:38:12 +0100 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Qemu-devel] [RFC PATCH 00/17] reverse debugging List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: QEMU Developers , Peter Maydell , Pavel Dovgalyuk On Sat, Apr 28, 2018 at 10:27 AM, Pavel Dovgalyuk wrote: > > >> -----Original Message----- >> From: Ciro Santilli [mailto:ciro.santilli@gmail.com] >> Sent: Saturday, April 28, 2018 11:13 AM >> To: Pavel Dovgalyuk >> Subject: Re: [RFC PATCH 00/17] reverse debugging >> >> Forgetting about debugging, I belive there is a deadlock in the replay >> at 63d426dfa4fbfac3d50cda3f553cd975de2b85ea , but it is rare. >> >> I have only reproduced it on ARM so far, and I haven't checked pre-patch. >> >> The setup is https://github.com/cirosantilli/qemu- >> test/tree/6a3497f0d84e7c86ef80f7322e24e8a149b93214 >> with images-ab21ef58deed8536bc159c2afd680a4fabd68510.zip >> >> Then try to run it several times with: >> >> i=0; while true; do date; echo $i; ../qemu-test/arm/rr; i=$(($i+1)); done >> >> I think the deadlock can happen in a few different places, but the >> most common is when the kernel is doing disk related stuff, the last >> messages before getting stuck are: > > It usually happens when there is some bugs in the implementation of the virtual devices. > Our customers mostly emulates x86-based systems, therefore most of > the ARM hardware is untested. > Hi Pete, do you know anything about this? Traces at: http://lists.nongnu.org/archive/html/qemu-devel/2018-04/msg05218.html command at: https://github.com/cirosantilli/qemu-test/blob/6a3497f0d84e7c86ef80f7322e24e8a149b93214/arm/rr @Pavel: I recommend always replying to both me and to qemu-devel to preserve a better history of our talk on the tracker. >> [ 11.530325] ALSA device list: >> [ 11.531451] No soundcards found. >> >> and what would follow on a normal replay would be: >> >> [ 11.551904] EXT4-fs (vda): couldn't mount as ext3 due to feature >> incompatibilities >> [ 11.619238] EXT4-fs (vda): mounted filesystem without journal. Opts: (null) >> >> I then attach GDB with: >> >> gdb -q ./arm-softmmu/qemu-system-arm `pgrep qemu` > > > > > Pavel Dovgalyuk >