Re: [PATCH v8 clocksource 2/5] clocksource: Retry clock read if long delays detected

2021-04-17 Thread Paul E. McKenney
On Sun, Apr 18, 2021 at 01:15:26AM +0200, Thomas Gleixner wrote: > On Sat, Apr 17 2021 at 15:54, Paul E. McKenney wrote: > > On Sat, Apr 17, 2021 at 02:24:23PM +0200, Thomas Gleixner wrote: > >> I so wish we could just delete all of this horror instead of making it > >> more horrible. > > > > Revis

Re: [PATCH v8 clocksource 2/5] clocksource: Retry clock read if long delays detected

2021-04-17 Thread Thomas Gleixner
On Sat, Apr 17 2021 at 15:54, Paul E. McKenney wrote: > On Sat, Apr 17, 2021 at 02:24:23PM +0200, Thomas Gleixner wrote: >> I so wish we could just delete all of this horror instead of making it >> more horrible. > > Revisit deleting it in five years if there are no issues, whatever > "issue" might

Re: [PATCH v8 clocksource 2/5] clocksource: Retry clock read if long delays detected

2021-04-17 Thread Paul E. McKenney
On Sat, Apr 17, 2021 at 02:24:23PM +0200, Thomas Gleixner wrote: > On Tue, Apr 13 2021 at 21:35, Paul E. McKenney wrote: > > #define WATCHDOG_INTERVAL (HZ >> 1) > > #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) > > +#define WATCHDOG_MAX_SKEW (NSEC_PER_SEC >> 6) > > That's ~15ms which is a tad l

Re: [PATCH v8 clocksource 2/5] clocksource: Retry clock read if long delays detected

2021-04-17 Thread Thomas Gleixner
On Tue, Apr 13 2021 at 21:35, Paul E. McKenney wrote: > #define WATCHDOG_INTERVAL (HZ >> 1) > #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) > +#define WATCHDOG_MAX_SKEW (NSEC_PER_SEC >> 6) That's ~15ms which is a tad large I'd say... > static void clocksource_watchdog_work(struct work_struc

Re: [PATCH v8 clocksource 2/5] clocksource: Retry clock read if long delays detected

2021-04-16 Thread Paul E. McKenney
On Fri, Apr 16, 2021 at 10:45:28PM +0200, Thomas Gleixner wrote: > On Tue, Apr 13 2021 at 21:35, Paul E. McKenney wrote: > > #define WATCHDOG_INTERVAL (HZ >> 1) > > #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) > > Didn't we discuss that the threshold is too big ? Indeed we did! How about lik

Re: [PATCH v8 clocksource 2/5] clocksource: Retry clock read if long delays detected

2021-04-16 Thread Thomas Gleixner
On Tue, Apr 13 2021 at 21:35, Paul E. McKenney wrote: > #define WATCHDOG_INTERVAL (HZ >> 1) > #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) Didn't we discuss that the threshold is too big ?