Messages in this thread | | | Date | Fri, 16 Sep 2005 12:33:03 +0200 (CEST) | From | Tim Schmielau <> | Subject | Re: early printk timings way off |
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On Fri, 16 Sep 2005, Tim Schmielau wrote:
> On Fri, 16 Sep 2005, Jesper Juhl wrote: > > It also doesn't > > explain why two lines, the first with timing value 0.000, and the next > > with 27.121 don't seem to match reality - the *actual* delta between > > printing those two lines is far lower than 27 seconds. > > Yes, this seems to be different, possibly unrelated problem. > It's interesting that the value jumps _exactly_to_zero_, though. > Will need to dig into the code...
Did that. The problem is that printk uses sched_clock() to determine the time, which just isn't supposed to be a reliable long-time clock. We need to base the output on a different clock.
Btw, the rate-limiting logic in printk.c looks 'interesting'. Will look into that, too.
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