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* [PATCH v2 0/7] Various tsc/clocksource fixes
@ 2018-04-30 10:00 Peter Zijlstra
  2018-04-30 10:00 ` [PATCH v2 1/7] x86,tsc: Always unregister clocksource_tsc_early Peter Zijlstra
                   ` (7 more replies)
  0 siblings, 8 replies; 20+ messages in thread
From: Peter Zijlstra @ 2018-04-30 10:00 UTC (permalink / raw)
  To: tglx; +Cc: linux-kernel, peterz, diego.viola, len.brown, rjw, rui.zhang

These patches are the result of the regression Diego reported against commit:

  aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource")

His Core2 triggers mark_tsc_unstable() while we're running with tsc-early,
which then results in us failing to unregister the clocksource.

Furthermore, since mark_tsc_unstable() only looks at the regular tsc
clocksource, we don't even mark tsc_early UNSTABLE or de-rate it, resulting in
it actually staying a desirable clocksource.

Fixing that is a little more tricky; albeit far less critical after we
guarantee to unregister tsc-early.

Please consider these for /urgent. I've used both Fixes and stable tags
on a bunch of them because the above commit is already in v4.16 and
would need stable help.

These patches have been tested on both a Core2 and an IVB. On IVB I've both
changed intel_idle to always report the TSC unstable and mucked about with the
TSC msr from userspace to tickle the watchdog paths.

---
Changes since v1

 - fix __clocksource_change_rating() locking
 - removed work->kthread->watchdog hoops
 - fixed up comment

^ permalink raw reply	[flat|nested] 20+ messages in thread

end of thread, other threads:[~2018-05-02 14:43 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-30 10:00 [PATCH v2 0/7] Various tsc/clocksource fixes Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 1/7] x86,tsc: Always unregister clocksource_tsc_early Peter Zijlstra
2018-05-02 14:12   ` [tip:timers/urgent] x86/tsc: " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 2/7] clocksource: Allow clocksource_mark_unstable() on unregisered clocksources Peter Zijlstra
2018-05-02 13:35   ` Thomas Gleixner
2018-05-02 13:53     ` Peter Zijlstra
2018-05-02 14:13       ` [tip:timers/urgent] clocksource: Allow clocksource_mark_unstable() on unregistered clocksources tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 3/7] clocksource: Initialize cs->wd_list Peter Zijlstra
2018-05-02 13:37   ` Thomas Gleixner
2018-05-02 13:55     ` Peter Zijlstra
2018-05-02 14:13   ` [tip:timers/urgent] " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 4/7] x86,tsc: Fix mark_tsc_unstable() Peter Zijlstra
2018-05-02 14:14   ` [tip:timers/urgent] x86/tsc: " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 5/7] clocksource: Consistent de-rate when marking unstable Peter Zijlstra
2018-05-02 14:14   ` [tip:timers/urgent] " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 6/7] clocksource: Rework stale comment Peter Zijlstra
2018-05-02 14:15   ` [tip:timers/urgent] " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 7/7] clocksource: Remove kthread Peter Zijlstra
2018-05-02 14:42   ` [tip:timers/core] " tip-bot for Peter Zijlstra
2018-05-01  9:12 ` [PATCH v2 0/7] Various tsc/clocksource fixes Rafael J. Wysocki

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