Messages in this thread | | | From | Nick Piggin <> | Subject | Re: [PATCH] scheduler: fix x86 regression in native_sched_clock | Date | Sat, 8 Dec 2007 11:50:50 +1100 |
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On Saturday 08 December 2007 03:48, Nick Piggin wrote: > On Friday 07 December 2007 22:17, Ingo Molnar wrote: > > * Nick Piggin <nickpiggin@yahoo.com.au> wrote: > > > > ah, printk_clock() still uses sched_clock(), not jiffies. So it's > > > > not the jiffies counter that goes back and forth, it's sched_clock() > > > > - so this is a printk timestamps anomaly, not related to jiffies. I > > > > thought we have fixed this bug in the printk code already: > > > > sched_clock() is a 'raw' interface that should not be used directly > > > > - the proper interface is cpu_clock(cpu). > > > > > > It's a single CPU box, so sched_clock() jumping would still be > > > problematic, no? > > > > sched_clock() is an internal API - the non-jumping API to be used by > > printk is cpu_clock(). > > You know why sched_clock jumps when the TSC frequency changes, right?
Ah, hmm, I don't know why I wrote that :)
I guess your patch is fairly complex but it should work if the plan is to convert all sched_clock users to use cpu_clock eg like lockdep as well.
So it looks good to me, thanks for fixing this.
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