Hi all, I am getting lots of Timer ISR/0: Timer went backwards error... due to which my dom0 is crashing. I tried hpet_force=1 argument for xen command line even then the problem presists. Other than that i could not find any solution on the net. Has this problem been resolved?? Iam using AMD Athlon(tm) 64bit processor, installed with FC6 & xen-3.2.0. Thanks, Sandesh Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2008-Jul-03 12:29 UTC
Re: [Xen-devel] Timer ISR/0: Timer went backwards error...
hpet_force=1 means nothing to Xen. To see what platform timer is being used, look for a line ''Platform timer is <foo>'' in Xen''s boot output. To change it, specify for example ''clocksource=hpet'' as a Xen boot parameter. Could you also send a few of the ''went backwards'' messages, so we can see how badly time is getting skewed. Perhaps we can work out where the issue arises from too -- it seems that a significant proprotion of those who have issues with these messages are seeing them on AMD boxes. I haven''t confirmed the correlation though. -- Keir On 3/7/08 12:44, "Sandesh" <sandesh.ahiremath@wipro.com> wrote:> Hi all, > I am getting lots of Timer ISR/0: Timer went backwards error... > due to which my dom0 is crashing. I tried hpet_force=1 argument for xen > command line even then the problem presists. Other than that i could not > find any solution on the net. > Has this problem been resolved?? > > Iam using AMD Athlon(tm) 64bit processor, installed with FC6 & > xen-3.2.0. > > Thanks, > Sandesh > > > Please do not print this email unless it is absolutely necessary. > > The information contained in this electronic message and any attachments to > this message are intended for the exclusive use of the addressee(s) and may > contain proprietary, confidential or privileged information. If you are not > the intended recipient, you should not disseminate, distribute or copy this > e-mail. Please notify the sender immediately and destroy all copies of this > message and any attachments. > > WARNING: Computer viruses can be transmitted via email. The recipient should > check this email and any attachments for the presence of viruses. The company > accepts no liability for any damage caused by any virus transmitted by this > email. > > www.wipro.com > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Thu, 2008-07-03 at 13:29 +0100, Keir Fraser wrote:> > Could you also send a few of the ''went backwards'' messages, so we can > see > how badly time is getting skewed. Perhaps we can work out where the > issue > arises from too -- it seems that a significant proprotion of those who > have > issues with these messages are seeing them on AMD boxes. I haven''t > confirmed > the correlation though.here is the log...repeated many times... Timer ISR/0: Time went backwards: delta=-9201298748592621662 delta_cpu=-9201298748582621662 shadow=73000238797 off=-9201298747702859870 processed=73890000000 cpu_processed=73880000000 0: 73880000000 Timer ISR/0: Time went backwards: delta=-9201298748575066948 delta_cpu=-9201298748565066948 shadow=73000238797 off=-9201298747685305644 processed=73890000000 cpu_processed=73880000000 0: 73880000000 Timer ISR/0: Time went backwards: delta=-9201298748557613457 delta_cpu=-9201298748547613457 shadow=73000238797 off=-9201298747667852175 processed=73890000000 cpu_processed=73880000000 0: 73880000000 Timer ISR/0: Time went backwards: delta=-9201298748540109642 delta_cpu=-9201298748530109642 shadow=73000238797 off=-9201298747650348375 processed=73890000000 cpu_processed=73880000000 0: 73880000000 Thanks, Sandesh Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Dan Magenheimer
2008-Jul-03 14:35 UTC
RE: [Xen-devel] Timer ISR/0: Timer went backwards error...
Sandesh -- hpet_force was a Xen parameter in Dave Winchell''s last hpet patch that hasn''t yet been accepted into the tree. However I think it would have only worked on hvm guests. Xen system time''s dependency on tsc is most susceptible on pre-Barcelona SMP AMD boxes (where tsc isn''t synchronized between processors), though yours seems to have a very bad skew. As Keir suggests "clocksource=hpet" as a Xen command line parameter will hopefully work for those boxes. Dan> -----Original Message----- > From: xen-devel-bounces@lists.xensource.com > [mailto:xen-devel-bounces@lists.xensource.com]On Behalf Of Keir Fraser > Sent: Thursday, July 03, 2008 6:30 AM > To: Sandesh; xen-devel@lists.xensource.com > Subject: Re: [Xen-devel] Timer ISR/0: Timer went backwards error... > > > hpet_force=1 means nothing to Xen. To see what platform timer > is being used, > look for a line ''Platform timer is <foo>'' in Xen''s boot > output. To change > it, specify for example ''clocksource=hpet'' as a Xen boot parameter. > > Could you also send a few of the ''went backwards'' messages, > so we can see > how badly time is getting skewed. Perhaps we can work out > where the issue > arises from too -- it seems that a significant proprotion of > those who have > issues with these messages are seeing them on AMD boxes. I > haven''t confirmed > the correlation though. > > -- Keir > > On 3/7/08 12:44, "Sandesh" <sandesh.ahiremath@wipro.com> wrote: > > > Hi all, > > I am getting lots of Timer ISR/0: Timer went backwards error... > > due to which my dom0 is crashing. I tried hpet_force=1 > argument for xen > > command line even then the problem presists. Other than > that i could not > > find any solution on the net. > > Has this problem been resolved?? > > > > Iam using AMD Athlon(tm) 64bit processor, installed with FC6 & > > xen-3.2.0. > > > > Thanks, > > Sandesh > > > > > > Please do not print this email unless it is absolutely necessary. > > > > The information contained in this electronic message and > any attachments to > > this message are intended for the exclusive use of the > addressee(s) and may > > contain proprietary, confidential or privileged > information. If you are not > > the intended recipient, you should not disseminate, > distribute or copy this > > e-mail. Please notify the sender immediately and destroy > all copies of this > > message and any attachments. > > > > WARNING: Computer viruses can be transmitted via email. The > recipient should > > check this email and any attachments for the presence of > viruses. The company > > accepts no liability for any damage caused by any virus > transmitted by this > > email. > > > > www.wipro.com > > > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xensource.com > > http://lists.xensource.com/xen-devel > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> As Keir suggests "clocksource=hpet" as > a Xen command line parameter will hopefully > work for those boxes.I tired "clocksource=hpet and clocksource=cyclone", and both of them failed to initialize respective timers, so by default APIC timer is getting installed. However with "clocksource=pit", init_pit seemed to have initialized PIT timer but it did not solve the problem. Am still getting the Time went backwards... To be more specific about the problem, it happens only when i try to return from the hypervisor kdb. But since many others have/had the same problem without the use of hypervisor kdb, i dont think its due to the kdb. I had never got this error before, so suerly kdb must be triggering something here. Thanks, Sandesh Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Mukesh Rathor
2008-Jul-03 20:40 UTC
[Xen-devel] Re: Timer ISR/0: Timer went backwards error...
> To be more specific about the problem, it happens only when i try to > return from the hypervisor kdb. But since many others have/had the sameThat''s a known issue in kdb. Like I mentioned in my kdb presentation, I''m still trying to get the timer stuff right, hopefully, in next release I''ll have it figured out and fixed. I am sure that is not the cause of your dom0 crash. Like I had mentioned in our offline emails, kdb is not properly tested on 32bit hyp, so the crash could well be something kdb related that needs to be investigated. Thanks, Mukesh Sandesh <sandesh.ahiremath <at> wipro.com> writes:> > > > As Keir suggests "clocksource=hpet" as > > a Xen command line parameter will hopefully > > work for those boxes. > I tired "clocksource=hpet and clocksource=cyclone", and both of them > failed to initialize respective timers, so by default APIC timer is > getting installed. > However with "clocksource=pit", init_pit seemed to have initialized PIT > timer but it did not solve the problem. Am still getting the Time went > backwards... > > To be more specific about the problem, it happens only when i try to > return from the hypervisor kdb. But since many others have/had the same > problem without the use of hypervisor kdb, i dont think its due to the > kdb. I had never got this error before, so suerly kdb must be triggering > something here. > > Thanks, > Sandesh > > Please do not print this email unless it is absolutely necessary. > > The information contained in this electronic message and any attachments tothis message are intended for> the exclusive use of the addressee(s) and may contain proprietary,confidential or privileged> information. If you are not the intended recipient, you should notdisseminate, distribute or copy this> e-mail. Please notify the sender immediately and destroy all copies of thismessage and any attachments.> > WARNING: Computer viruses can be transmitted via email. The recipient shouldcheck this email and any> attachments for the presence of viruses. The company accepts no liability forany damage caused by any> virus transmitted by this email. > > www.wipro.com >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2008-Jul-03 22:56 UTC
Re: [Xen-devel] Timer ISR/0: Timer went backwards error...
On 3/7/08 17:43, "Sandesh" <sandesh.ahiremath@wipro.com> wrote:> To be more specific about the problem, it happens only when i try to > return from the hypervisor kdb. But since many others have/had the same > problem without the use of hypervisor kdb, i dont think its due to the > kdb. I had never got this error before, so suerly kdb must be triggering > something here.Quite a relevant bit of information I''d say. It''s certainly related, since time structures in Xen will not be updated and kept synchronised while kdb has the system locked down. Indeed the time deltas you see are huge, so the timeout in kdb has sent time handling haywire. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel