Re: Problem about CPU stalling in hrtimer_intterrupts()

From	Thomas Gleixner <tglx@linutronix.de>
Newsgroups	linux.kernel
Subject	Re: Problem about CPU stalling in hrtimer_intterrupts()
Date	2015-10-24 12:00 +0200
Message-ID	<qn3Me-575-1@gated-at.bofh.it> (permalink)
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On Thu, 22 Oct 2015, Yang Yingliang wrote:

> But I found out when the cpu is stalling, basenow.tv64(7676664221321) is
> bigger than ktime_get().tv64(7336008904750) in hrtimer_interrupt() and
> the timer->_softexpires is 7336288000000. This makes it can not finish
> the while loop until ktime_get().tv64 arrives basenow.tv64.
> 
> Is it correct that basenow bigger than ktime_get() ?

You only can compare basenow and ktime_get() for the clock monotonic
base. If you are actually observing this on clock monotonic base then
base->offset of clock monotonic is not 0, which should never happen.

Thanks,

	tglx
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Thread

Problem about CPU stalling in hrtimer_intterrupts() Yang Yingliang <yangyingliang@huawei.com> - 2015-10-22 08:50 +0200
  Re: Problem about CPU stalling in hrtimer_intterrupts() Thomas Gleixner <tglx@linutronix.de> - 2015-10-22 09:50 +0200
    Re: Problem about CPU stalling in hrtimer_intterrupts() Ding Tianhong <dingtianhong@huawei.com> - 2015-10-22 11:40 +0200
      Re: Problem about CPU stalling in hrtimer_intterrupts() Thomas Gleixner <tglx@linutronix.de> - 2015-10-22 12:30 +0200
        Re: Problem about CPU stalling in hrtimer_intterrupts() Yang Yingliang <yangyingliang@huawei.com> - 2015-10-22 15:50 +0200
          Re: Problem about CPU stalling in hrtimer_intterrupts() Thomas Gleixner <tglx@linutronix.de> - 2015-10-24 12:00 +0200

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