Re: 2.6.35-rc1 regression with pvclock and smp guests

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

 



On 10/07/2010 02:12 PM, Arjan Koers wrote:
On 2010-10-03 01:42, Zachary Amsden wrote:
...
Umm...  do you guys have this commit?  This is supposed to address the
issue where the guest keeps resetting the TSC.  A guest which does that
will break kvmclock.  It only happens on SMP, and it's much worse on AMD
CPUs...

sound like your scenario.

commit bd59fc8ff95126f27b7a0df1b6cc602aa428812d
Author: Zachary Amsden<zamsden@xxxxxxxxxx>
Date:   Thu Aug 19 22:07:26 2010 -1000

This commit fixes the problem:

commit aad07c4f92bae2edaa42bcef84c2afdd0d082458
Author: Zachary Amsden<zamsden@xxxxxxxxxx>
Date:   Thu Aug 19 22:07:19 2010 -1000

     KVM: x86: Move TSC reset out of vmcb_init

     The VMCB is reset whenever we receive a startup IPI, so Linux is setting
     TSC back to zero happens very late in the boot process and destabilizing
     the TSC.  Instead, just set TSC to zero once at VCPU creation time.

     Why the separate patch?  So git-bisect is your friend.

Okay, apparently I need to go poke around 2.6.35 and see what patches made it there and what patches didn't.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux