Messages in this thread | | | Subject | Re: max_clock of the patch "sched_clock: fix cpu_clock()" | From | Peter Zijlstra <> | Date | Tue, 16 Sep 2008 06:48:30 +0200 |
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On Tue, 2008-09-16 at 11:01 +0800, Lin Ming wrote: > Hi, Peter, > > I have a question of the max_clock in below patch, > commit 354879bb977e06695993435745f06a0f6d39ce2b > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Mon Aug 25 17:15:34 2008 +0200 > > sched_clock: fix cpu_clock() > > The original code to calculate min_clock and max_clock is, > min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC; > max_clock = min_clock + TICK_NSEC; > > Now it's changed to, > min_clock = wrap_max(scd->tick_gtod, scd->clock); > max_clock = scd->tick_gtod + TICK_NSEC; > > Is this max_clock still correct if, in a rare case, irq is disabled for > many ticks?
Nope, it wont (nor would the old), but having irqs disabled for that long would be something worth fixing.
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