From: Avi Kivity <avi@redhat.com>
To: Arjan Koers <0h61vkll2ly8@xutrox.com>
Cc: kvm@vger.kernel.org, Zachary Amsden <zamsden@redhat.com>
Subject: Re: 2.6.35-rc1 regression with pvclock and smp guests
Date: Wed, 28 Jul 2010 13:37:38 +0300 [thread overview]
Message-ID: <4C500872.1020809@redhat.com> (raw)
In-Reply-To: <4C4F48D0.8090609@xutrox.com>
On 07/28/2010 12:00 AM, Arjan Koers wrote:
> On 2010-07-26 20:59, Arjan Koers wrote:
>
>> I ran into the same problem. 2.6.34.1 and 2.6.35-rc6 SMP guest
>> kernels hang during boot.
>
> It appears that last is way ahead of ret twice.
> The kernel boots with this debug patch that makes the clock go
> backwards if the difference is big:
>
> last = atomic64_read(&last_value);
> do {
> - if (ret< last)
> - return last;
> + if (ret< last) {
> + if ( last - ret< 25000000 )
> + return last;
> + else
> + printk("pvclock backwards: ret = %llx; last = %llx\n", ret, last);
> + }
> last = atomic64_cmpxchg(&last_value, last, ret);
> } while (unlikely(last != ret));
>
>
>
> [ 0.037122] Total of 2 processors activated (11198.08 BogoMIPS).
> [ 0.037118] x86 PAT enabled: cpu 1, old 0x0, new 0x7010600070106
> [ 0.040000] pvclock backwards: ret = 108373705fe2; last = 210aff61470a
Zaaaacchhhh?!
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2010-07-28 10:37 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-22 12:53 2.6.35-rc1 regression with pvclock and smp guests Andre Przywara
2010-07-25 8:44 ` Avi Kivity
2010-07-26 8:47 ` Andre Przywara
2010-07-26 18:59 ` Arjan Koers
2010-07-27 21:00 ` Arjan Koers
2010-07-28 10:37 ` Avi Kivity [this message]
2010-07-31 0:34 ` Arjan Koers
2010-07-31 1:38 ` Zachary Amsden
2010-07-31 11:50 ` Arjan Koers
2010-07-31 2:39 ` Zachary Amsden
2010-07-31 11:53 ` Arjan Koers
2010-07-31 16:36 ` Arjan Koers
2010-07-31 19:45 ` Arjan Koers
2010-07-31 23:55 ` Zachary Amsden
2010-08-02 14:43 ` Glauber Costa
2010-08-02 16:16 ` Arjan Koers
2010-08-02 18:07 ` Glauber Costa
2010-08-02 20:26 ` Zachary Amsden
2010-08-02 21:10 ` Glauber Costa
2010-08-02 21:35 ` Arjan Koers
2010-08-03 0:00 ` Zachary Amsden
2010-09-28 11:16 ` Michael Tokarev
2010-09-29 8:12 ` Michael Tokarev
2010-09-29 8:28 ` Avi Kivity
2010-09-29 9:17 ` Michael Tokarev
2010-09-29 9:19 ` Michael Tokarev
2010-09-29 19:26 ` Arjan Koers
2010-09-30 7:55 ` Michael Tokarev
2010-09-30 9:59 ` Michael Tokarev
2010-09-30 13:54 ` Zachary Amsden
2010-09-30 15:12 ` Michael Tokarev
2010-09-30 15:32 ` Zachary Amsden
2010-09-30 18:49 ` Arjan Koers
2010-09-30 19:05 ` Marcelo Tosatti
2010-09-30 20:16 ` Arjan Koers
2010-09-30 23:02 ` Michael Tokarev
2010-09-30 23:07 ` Michael Tokarev
2010-10-01 1:13 ` Zachary Amsden
2010-10-02 5:35 ` Zachary Amsden
2010-10-02 7:35 ` Michael Tokarev
2010-10-02 7:40 ` Michael Tokarev
2010-10-02 7:50 ` Michael Tokarev
2010-10-02 16:10 ` Arjan Koers
2010-10-02 20:26 ` Michael Tokarev
2010-10-02 23:42 ` Zachary Amsden
2010-10-03 8:27 ` Michael Tokarev
2010-10-08 0:12 ` Arjan Koers
2010-10-08 2:47 ` Zachary Amsden
2010-10-08 22:06 ` Marcelo Tosatti
2010-10-09 1:10 ` Arjan Koers
2010-10-09 2:27 ` Zachary Amsden
2010-10-09 6:29 ` Michael Tokarev
2010-10-09 8:59 ` Arjan Koers
2010-10-11 20:47 ` Zachary Amsden
2010-10-13 12:18 ` Glauber Costa
2010-10-10 1:20 ` Arjan Koers
2010-10-11 17:53 ` Anthony Liguori
2010-10-11 18:36 ` Marcelo Tosatti
2010-10-09 2:29 ` Zachary Amsden
2010-10-10 1:26 ` Arjan Koers
2010-10-20 20:47 ` Arjan Koers
2010-10-09 7:59 ` Michael Tokarev
2010-10-09 8:31 ` Michael Tokarev
2010-10-02 21:55 ` Zachary Amsden
2010-10-03 8:16 ` Michael Tokarev
2010-10-03 8:22 ` Avi Kivity
2010-10-03 8:30 ` Michael Tokarev
2010-07-27 10:03 ` Avi Kivity
2010-07-27 11:49 ` Andre Przywara
2010-07-27 12:06 ` Avi Kivity
2010-07-27 12:21 ` Andre Przywara
2010-07-27 12:34 ` Avi Kivity
2010-07-27 13:48 ` Andre Przywara
2010-07-27 13:58 ` Avi Kivity
2010-07-27 14:55 ` Andre Przywara
2010-07-27 21:51 ` Andre Przywara
2010-07-28 3:00 ` Zachary Amsden
2010-07-28 7:55 ` Andre Przywara
2010-07-28 12:25 ` Andre Przywara
2010-07-30 22:54 ` Zachary Amsden
2010-08-02 10:12 ` Andre Przywara
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