Messages in this thread | | | Subject | Re: x86-tip tsc/tick gripage | From | Mike Galbraith <> | Date | Thu, 27 Apr 2017 07:26:55 +0200 |
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On Wed, 2017-04-26 at 14:30 +0200, Mike Galbraith wrote: > On Wed, 2017-04-26 at 13:39 +0200, Mike Galbraith wrote: > > On Wed, 2017-04-26 at 12:26 +0200, Peter Zijlstra wrote: > > > On Wed, Apr 26, 2017 at 10:57:42AM +0200, Mike Galbraith wrote: > > > > > > > Both still lose their TSC. > > > > > > > > [ 11.982468] tsc: Refined TSC clocksource calibration: 2260.999 MHz > > > > [ 11.994275] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x20974a4d8bb, max_idle_ns: 440795246623 ns > > > > [ 13.064172] clocksource: Switched to clocksource tsc > > > > [ 240.247851] clocksource: timekeeping watchdog on CPU23: Marking clocksource 'tsc' as unstable because the skew is too large: > > > > [ 240.462501] clocksource: 'tsc' cs_now: 108fe5be09f cs_last: b90a6a0676 mask: ffffffffffffffff > > > > [ 240.675057] tsc: Marking TSC unstable due to clocksource watchdog > > > > > > > > > And they didn't use to? We don't typically write to TSC or TSC_ADJUST > > > and thus would not cause such behaviour. > > > > Nope. > > DL980 seems perfectly happy with master.today.. so off we go.
hm, this bit of huge trace looks less than wonderful.
<idle>-0 [041] ..s2 317.304657: timer_expire_entry: timer=ffffffff820d6600 function=clocksource_watchdog now=4294971392 <idle>-0 [041] d.s4 317.304660: timer_start: timer=ffffffff820d6600 function=clocksource_watchdog expires=4294916631 [timeout=-54761] cpu=42 idx=19 flags= <idle>-0 [041] ..s2 317.304660: timer_expire_exit: timer=ffffffff820d6600 ^^^^^^^^^^^^^^
1.1 megalines later, we finally meet function=clocksource_watchdog again, and have a cow. <idle>-0 [043] d.s3 489.511620: timer_cancel: timer=ffffffff820d6600 <idle>-0 [043] ..s2 489.511621: timer_expire_entry: timer=ffffffff820d6600 function=clocksource_watchdog now=4295014443 <idle>-0 [043] ..s2 489.511628: clocksource_watchdog: timekeeping watchdog on CPU43: Marking clocksource 'tsc' as unstable because the skew is too large: <idle>-0 [043] ..s2 489.511630: clocksource_watchdog: 'hpet' wd_now: a1cbfa1a wd_last: ed7acfe mask: ffffffff <idle>-0 [043] ..s2 489.511630: clocksource_watchdog: 'tsc' cs_now: 1c24ee60f22 cs_last: 167a92e836f mask: ffffffffffffffff
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