Re: tip.today - scheduler bam boom crash (cpu hotplug)

Wanpeng Li
2017-03-01T13:39:43Z

2017-02-28 16:11 GMT+08:00 Wanpeng Li <kernellwp@gmail.com>:
> 2017-02-28 16:08 GMT+08:00 Peter Zijlstra <peterz@infradead.org>:
>> On Tue, Feb 28, 2017 at 09:51:07AM +0800, Wanpeng Li wrote:
>>> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
>>> index 4e95b2e..ed8eda4 100644
>>> --- a/arch/x86/kernel/cpu/amd.c
>>> +++ b/arch/x86/kernel/cpu/amd.c
>>> @@ -557,7 +557,7 @@ static void early_init_amd(struct cpuinfo_x86 *c)
>>> set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
>>> if (check_tsc_unstable())
>>> clear_sched_clock_stable();
>>> - } else {
>>> + } else if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
>>> clear_sched_clock_stable();
>>> }
>>
>> That's wrong, you can have HYPERVISOR and still use
>> native_sched_clock() (lguest does that for one).
>
> My posting delay to check this in tsc_init().

Does it make sense?

Regards,
Wanpeng Li