From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: xcs segfaults on vm shutdown Date: Mon, 14 Mar 2005 11:29:51 -0600 Message-ID: <4235CA0F.2010906@us.ibm.com> References: <20050312195956.GA2265@archdale.cs.washington.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In-Reply-To: <20050312195956.GA2265@archdale.cs.washington.edu> Sender: xen-devel-admin@lists.sourceforge.net Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Richard Sterling Cox Cc: xen-devel@lists.sourceforge.net List-Id: xen-devel@lists.xenproject.org Richard Sterling Cox wrote: >hi, > >I'm experiencing regular seg-faults of the xcs daemon during vm >shutdown operations (occurring somewhere between 5 and 25 VMs run, >typically). > > I've seen xcs crash a number of times with vm-tools. What arguments were you passing to vm-shutdown? The default operation is to simply send a CMSG_SHUTDOWN to the domain. If you're doing a '-d' which invokes xc_destroy, I think that perhaps what's happening is that xcs is not gracefully handling a disappearing VM. Regards, >xen: unstable patched through 2005-03-07 >dom0: linux-2.6.10-xen0 / Fedora Core 3 >gcc: 3.4.2 20041017 (Red Hat 3.4.2-6.fc3) >vmtools: 0.0.3 I believe, but they report (-V) 0.0.1, which is not > true >(not using xend) > >The errors usually seem to occur while running 'vm-shutdown'. > >I have been running 'xcs -i' under gdb and found that, at least twice, >the error is at xen/tools/xcs/ctrl_interface.c:143. Here is the output >of one such session (the error is repeatable enough that I should be >able to provide other info if anyone is interested): > >Program received signal SIGSEGV, Segmentation fault. >0x080490b9 in ctrl_chan_request_to_read (cc=0x8050a60) at ctrl_interface.c:143 >143 return (RING_HAS_UNCONSUMED_REQUESTS(CTRL_RING, &cc->tx_ring)); > >(gdb) bt >#0 0x080490b9 in ctrl_chan_request_to_read (cc=0x8050a60) at ctrl_interface.c:143 >#1 0x0804a8d7 in handle_ctrl_if () at xcs.c:550 >#2 0x0804ae93 in main (argc=2, argv=0xbffffa74) at xcs.c:737 >(gdb) print cc >$1 = (control_channel_t *) 0x8050a60 >(gdb) print *cc >$2 = {connected = 1, ref_count = 1, type = 0, remote_dom = 26, local_port = 73, remote_port = 1, > interface = 0xb7ff0800, tx_ring = {rsp_prod_pvt = 0, req_cons = 0, sring = 0xb7ff0800}, > rx_ring = {req_prod_pvt = 0, rsp_cons = 0, sring = 0xb7ff0a08}, virq = 0} >(gdb) print *(cc->tx_ring->sring) >Cannot access memory at address 0xb7ff0800 >(gdb) up >#1 0x0804a8d7 in handle_ctrl_if () at xcs.c:550 >550 while (ctrl_chan_request_to_read(cc)) >(gdb) print chan >$4 = 73 >(gdb) print cc_list[chan] >$6 = (control_channel_t *) 0x8050a60 > > >rick > > > >------------------------------------------------------- >SF email is sponsored by - The IT Product Guide >Read honest & candid reviews on hundreds of IT Products from real users. >Discover which products truly live up to the hype. Start reading now. >http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >_______________________________________________ >Xen-devel mailing list >Xen-devel@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/xen-devel > > > ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click