Hi, I have a problem with too fast clock in dom0. The clock is 3-4times faster than ''real'' clock. In users list I got an advice suggesting that it is a hw bug. But I have no other problem with the hw and I hope it is a xen bug (or my misconfiguration) and it can be fixed or workarounded. It happens on a notebook compaq evo N115 (Duron 996MHz). On my desktop with similar configuration there is no problem (xm dmesg attached for both). I tried to locate the bug myself but with no luck :( Could you please suggest some hints where to start debugging? -- Tomas Kouba _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> I have a problem with too fast clock in dom0. > The clock is 3-4times faster than ''real'' clock. > In users list I got an advice suggesting that it is a hw bug. > But I have no other problem with the hw and I hope it is a > xen bug (or my misconfiguration) and it can be fixed or workarounded. > > It happens on a notebook compaq evo N115 (Duron 996MHz). > On my desktop with similar configuration there is no problem > (xm dmesg attached for both). > > I tried to locate the bug myself but with no luck :( Could > you please suggest some hints where to start debugging?Please can you try putting ''lapic'' on the grub xen command line. Haing the dom0 dmesg output would be useful too. I think we only have one other current report of this ''time too fast'' bug, so it must be quite hardware specific. I presume you''re using 3.0.0? Ian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> Please can you try putting ''lapic'' on the grub xen command line. Haing > the dom0 dmesg output would be useful too.I have trie lapic and nlapic with no noticable difference. Dmesg outupts for both attached.> I presume you''re using 3.0.0?Yes I do. Compiled from mercurial. -- Tomas Kouba _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> > Please can you try putting ''lapic'' on the grub xen command > line. Haing > > the dom0 dmesg output would be useful too. > > I have trie lapic and nlapic with no noticable difference. > Dmesg outupts for both attached.Hmm, shame this didn''t work. I''d have been interested to see the "xm dmesg" output from the "lapic" case. Ian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Ian Pratt wrote:> > > Please can you try putting ''lapic'' on the grub xen command > > >>line. Haing >> >> >>>the dom0 dmesg output would be useful too. >>> >>> >>I have trie lapic and nlapic with no noticable difference. >>Dmesg outupts for both attached. >> >> > >Hmm, shame this didn''t work. > >I''d have been interested to see the "xm dmesg" output from the "lapic" >case. > >Attached. The lines (XEN) Local APIC disabled by BIOS -- you can enable it with "lapic" (XEN) Local APIC not detected. Using dummy APIC emulation are a bit strange for me. The BIOS is quite simple PheonixBIOS with no options regarding APIC. lapic kernel parameter was *surely* used -- Tomas Kouba _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> (XEN) Local APIC disabled by BIOS -- you can enable it with "lapic" > (XEN) Local APIC not detected. Using dummy APIC emulation > > are a bit strange for me. The BIOS is quite simple > PheonixBIOS with no options regarding APIC. > lapic kernel parameter was *surely* usedIt''s not that uncommon for the bios to disable the apic. I suppose it''s possible that Duron''s don''t have one anyway. One thing that might be worth doing is to write a little program that sits in a loop calling gettimeofday and reporting the delta from the previous call [hint: convert the output into a 64b long long by u.tv_usec + (unsigned long long)u.tv_sec*1000000; ] It''ll be interesting to see whether time runs forward smoothly or jumps ahead in steps. If time is progressing smoothly, then I guess the problem with your laptop must be that the PIT that Xen uses is being subverted by something else. No idea what, though -- perhaps something hidden in SMM. Ian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 26 Dec 2005, at 10:28, Tomas Kouba wrote:> Attached. > The lines > > (XEN) Local APIC disabled by BIOS -- you can enable it with "lapic" > (XEN) Local APIC not detected. Using dummy APIC emulation > > are a bit strange for me. The BIOS is quite simple PheonixBIOS with no > options regarding APIC. > lapic kernel parameter was *surely* usedIf lapic had been passed on Xen''s command line then you would not have got the first line from Xen (the one that ends "...you can enable it with "lapic""). -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser wrote:> > On 26 Dec 2005, at 10:28, Tomas Kouba wrote: > >> Attached. >> The lines >> >> (XEN) Local APIC disabled by BIOS -- you can enable it with "lapic" >> (XEN) Local APIC not detected. Using dummy APIC emulation >> >> are a bit strange for me. The BIOS is quite simple PheonixBIOS with >> no options regarding APIC. >> lapic kernel parameter was *surely* used > > > If lapic had been passed on Xen''s command line then you would not have > got the first line from Xen (the one that ends "...you can enable it > with "lapic"").It seemed strange to me too. But: $ xm dmesg | grep lapic (XEN) Local APIC disabled by BIOS -- you can enable it with "lapic" $ cat /proc/cmdline lapic root=/dev/hda6 ro console=tty1 Am I missing something? Btw. I have tried live CDs on the notebook and 2.0.6 works fine (clock runs ok) but 3.0 is again too fast. -- Tomas Kouba _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 29 Dec 2005, at 19:36, Tomas Kouba wrote:> It seemed strange to me too. But: > $ xm dmesg | grep lapic > (XEN) Local APIC disabled by BIOS -- you can enable it with "lapic" > $ cat /proc/cmdline > lapic root=/dev/hda6 ro console=tty1 > > Am I missing something?You added it to the wrong command line. That''s Linux''s command line, not Xen''s. If you boot via GRUB, ''lapic'' gets added the line immediately above the one you currently added it to. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel