[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] RE: latest xen-unstable fails to boot on Dell D630 (likely hpet/Cstate problem)



> But I'll give bisecting a try.

Looks like the problem has been around for awhile.  It appears
the problem starts at c/s 20073.  Xiantao cc'ed since 20073
was his patch.

20070 boots OK without max_cstate=2

20072 boots most of the way without max_cstate=2 but crashes
      before a login prompt (when xend is starting I think)

20073 FAILS to boot without max_cstate=2 but crashes
      before a login prompt

20082 FAILS to boot without max_cstate=2 but crashes
      before a login prompt with max_cstate=2

20143 FAILS to boot without max_cstate=2 but boots OK
      with max_cstate=2

Note that I have NOT bisected tools, just the hypervisor
so the crashes are likely due to a newer xend failing on
an older hypervisor (which is irrelevant to this problem).

> -----Original Message-----
> From: Dan Magenheimer 
> Sent: Tuesday, December 08, 2009 10:42 AM
> To: Yu, Ke; Xen-Devel (E-mail)
> Subject: RE: latest xen-unstable fails to boot on Dell D630 (likely
> hpet/Cstate problem)
> 
> 
> > case, if convenient, could you help to do some bisect to see 
> > which cset cause this bug?
> 
> I can do this, but because it is often no longer easy to
> bisect Xen because of interdependencies with other
> components, I was hoping that Keir or you or someone might
> have some idea of what changeset might have caused the regression.
> But I'll give bisecting a try.
> 
> > max_cstate=2), when dom0 hangs, is xen still alive, E.g. can 
> > Xen response to three Ctrl-'A' in serial?
> 
> Unfortunately, I can't seem to get a Xen console working on
> the Merom machine, and the problem can't be reproduced on
> my other machine where the Xen console is working (because
> Conroe doesn't support deep C).
> 
> > -----Original Message-----
> > From: Yu, Ke [mailto:ke.yu@xxxxxxxxx]
> > Sent: Tuesday, December 08, 2009 12:08 AM
> > To: Dan Magenheimer; Xen-Devel (E-mail)
> > Subject: RE: latest xen-unstable fails to boot on Dell D630 (likely
> > hpet/Cstate problem)
> > 
> > 
> > >-----Original Message-----
> > >In this thread, I observed that I was unable to
> > >provoke deep C state (C3) on my Dell D630, which has
> > >a Intel Merom (dual-core laptop) processor.  At that
> > >time, when I tried enabling hpetbroadcast, dom0 boot failed.
> > >
> > >http://lists.xensource.com/archives/html/xen-devel/2009-10/ms
> > g01027.html
> > >
> > >As it turned out, all RHEL5-based (maybe RHEL4- also) dom0
> > >default installation run /sbin/hwclock, which IIRC takes
> > >the RTC away from Xen and gives it to dom0.  Since the
> > >Xen hpet emulation does not do RTC emulation, bad things
> > >then happen when a deep Cstate is entered (dom0 apparently
> > >never wakes up).  I think Ke Yu has also reproduced this problem.
> > >
> > >Sometime in the last few weeks, some patch in xen-unstable
> > >apparently changed some defaults and xen-unstable will
> > >no longer boot with this processor/dom0, with or without
> > >hpetbroadcast on the Xen command line.  However, specifying
> > >max_cstate=2 on the Xen command line allows a successful
> > >dom0 boot, so I suspect the problem is the same (or at
> > >least very similar).
> > >
> > >I did a quick scan for hpet changes and found c/s 20497,
> > >but backing it out made no difference.
> > >
> > >I have a workaround for now, but since it is likely that
> > >many customers (including all of Oracle's OVS customers)
> > >use a RHEL5-based dom0 boot sequence, and Merom processors
> > >work fine otherwise, it would be nice to get this identified
> > >and fixed before 4.0.
> > 
> > Let's firstly figure out which component the issue resides. 
> > 
> > Firstly, in the default boot (i.e. without specifying 
> > max_cstate=2), when dom0 hangs, is xen still alive, E.g. can 
> > Xen response to three Ctrl-'A' in serial?
> > 
> > If only dom0 hangs, it is probably that RTC malfunction make 
> > incorrect dom0 time and lead dom0 fail to boot. Then RTC 
> > emulation in hypervisor should fix this issue.
> > 
> > If Xen also hangs, it should be another bug, i.e. hpet 
> > broadcast does not wake up CPU in deep C states. in this 
> > case, if convenient, could you help to do some bisect to see 
> > which cset cause this bug?
> > 
> > Best Regards
> > Ke
> > 
> > 
>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.