Messages in this thread | | | Date | Mon, 30 Apr 2018 12:00:08 +0200 | From | Peter Zijlstra <> | Subject | [PATCH v2 0/7] Various tsc/clocksource fixes |
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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
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