From: Avi Kivity <avi@redhat.com>
To: Zachary Amsden <zamsden@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Glauber Costa <glommer@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeremy Fitzhardinge <jeremy@goop.org>,
Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH 1/5] Add a global synchronization point for pvclock
Date: Wed, 21 Apr 2010 11:08:22 +0300 [thread overview]
Message-ID: <4BCEB276.6050909@redhat.com> (raw)
In-Reply-To: <4BCE4153.4010801@redhat.com>
On 04/21/2010 03:05 AM, Zachary Amsden wrote:
> On 04/19/2010 11:39 PM, Avi Kivity wrote:
>> On 04/19/2010 09:35 PM, Zachary Amsden wrote:
>>>>>> Sockets and boards too? (IOW, how reliable is TSC_RELIABLE)?
>>>>> Not sure, IIRC we clear that when the TSC sync test fails, eg when we
>>>>> mark the tsc clocksource unusable.
>>>>
>>>> Worrying. By the time we detect this the guest may already have
>>>> gotten confused by clocks going backwards.
>>>
>>>
>>> Upstream, we are marking the TSC unstable preemptively when hardware
>>> which will eventually sync test is detected, so this should be fine.
>>
>> ENOPARSE?
>>
>
> Instead of detecting TSC warp, c1e_idle, power_saving_mwait_init,
> tsc_check_state, dmi_mark_tsc_unstable all do something similar to
> this to disable TSC before warp even occurs:
>
> static void c1e_idle(void)
> {
> if (need_resched())
> return;
>
> if (!c1e_detected) {
> u32 lo, hi;
>
> rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
> if (lo & K8_INTP_C1E_ACTIVE_MASK) {
> c1e_detected = 1;
> if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
> mark_tsc_unstable("TSC halt in AMD C1E");
> printk(KERN_INFO "System has AMD C1E enabled\n");
> set_cpu_cap(&boot_cpu_data, X86_FEATURE_AMDC1E);
> }
> }
>
>
That works within a socket; but multiple socket machines need not feed
all sockets from the same crystal and reset line (esp. likely for
multiple board machines, but might even happen with single board
FSB-less processors).
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2010-04-21 8:08 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-15 18:37 [PATCH 0/5] pv clock misc fixes Glauber Costa
2010-04-15 18:37 ` [PATCH 1/5] Add a global synchronization point for pvclock Glauber Costa
2010-04-15 18:37 ` [PATCH 2/5] change msr numbers for kvmclock Glauber Costa
2010-04-15 18:37 ` [PATCH 3/5] Try using new kvm clock msrs Glauber Costa
2010-04-15 18:37 ` [PATCH 4/5] export new cpuid KVM_CAP Glauber Costa
2010-04-15 18:37 ` [PATCH 5/5] add documentation about kvmclock Glauber Costa
2010-04-15 19:28 ` Randy Dunlap
2010-04-15 20:10 ` Glauber Costa
2010-04-17 18:58 ` [PATCH 4/5] export new cpuid KVM_CAP Avi Kivity
2010-04-19 14:50 ` Glauber Costa
2010-04-20 9:29 ` Avi Kivity
2010-04-17 18:55 ` [PATCH 3/5] Try using new kvm clock msrs Avi Kivity
2010-04-17 18:51 ` [PATCH 2/5] change msr numbers for kvmclock Avi Kivity
2010-04-16 20:23 ` [PATCH 1/5] Add a global synchronization point for pvclock Marcelo Tosatti
2010-04-16 20:36 ` Jeremy Fitzhardinge
2010-04-16 21:05 ` Zachary Amsden
2010-04-19 10:39 ` Peter Zijlstra
2010-04-19 10:50 ` Avi Kivity
2010-04-19 11:05 ` Peter Zijlstra
2010-04-19 11:10 ` Avi Kivity
2010-04-19 14:21 ` Glauber Costa
2010-04-19 14:33 ` Avi Kivity
2010-04-19 14:46 ` Peter Zijlstra
2010-04-19 16:18 ` Jeremy Fitzhardinge
2010-04-20 9:31 ` Avi Kivity
2010-04-20 18:23 ` Jeremy Fitzhardinge
2010-04-20 18:54 ` Avi Kivity
2010-04-20 19:42 ` Jeremy Fitzhardinge
2010-04-21 0:07 ` Zachary Amsden
2010-04-22 13:11 ` Glauber Costa
2010-04-23 1:44 ` Zachary Amsden
2010-04-23 9:34 ` Avi Kivity
2010-04-23 19:22 ` Jeremy Fitzhardinge
2010-04-23 19:25 ` Avi Kivity
2010-04-23 21:31 ` Zachary Amsden
2010-04-23 21:35 ` Jeremy Fitzhardinge
2010-04-23 21:41 ` Zachary Amsden
2010-04-24 9:30 ` Avi Kivity
2010-04-24 9:29 ` Avi Kivity
2010-04-19 16:11 ` Jeremy Fitzhardinge
2010-04-19 14:26 ` Glauber Costa
2010-04-19 16:19 ` Jeremy Fitzhardinge
2010-04-19 18:25 ` Glauber Costa
2010-04-20 1:57 ` Marcelo Tosatti
2010-04-20 9:35 ` Avi Kivity
2010-04-20 12:59 ` Glauber Costa
2010-04-20 15:16 ` Avi Kivity
2010-04-21 0:01 ` Zachary Amsden
2010-04-21 8:06 ` Avi Kivity
2010-04-17 18:48 ` Avi Kivity
2010-04-17 18:49 ` Avi Kivity
2010-04-19 10:43 ` Peter Zijlstra
2010-04-19 10:47 ` Avi Kivity
2010-04-19 10:56 ` Peter Zijlstra
2010-04-19 11:13 ` Avi Kivity
2010-04-19 11:19 ` Peter Zijlstra
2010-04-19 11:40 ` Avi Kivity
2010-04-19 14:32 ` Glauber Costa
2010-04-19 14:37 ` Avi Kivity
2010-04-19 10:46 ` Peter Zijlstra
2010-04-19 10:49 ` Avi Kivity
2010-04-19 10:51 ` Peter Zijlstra
2010-04-19 10:54 ` Avi Kivity
2010-04-19 18:35 ` Zachary Amsden
2010-04-20 9:39 ` Avi Kivity
2010-04-21 0:05 ` Zachary Amsden
2010-04-21 8:08 ` Avi Kivity [this message]
2010-04-19 10:49 ` Peter Zijlstra
2010-04-19 10:53 ` Avi Kivity
2010-04-19 10:59 ` Peter Zijlstra
2010-04-19 11:35 ` Avi Kivity
2010-10-25 23:30 ` Jeremy Fitzhardinge
2010-10-26 8:14 ` Avi Kivity
2010-10-26 10:49 ` Glauber Costa
2010-10-26 17:04 ` Jeremy Fitzhardinge
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