Messages in this thread | | | Date | Wed, 17 May 2006 00:36:14 +0200 | From | Martin Peschke <> | Subject | Re: [RFC] [Patch 7/8] statistics infrastructure - exploitation prerequisite |
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Andrew Morton wrote: > Martin Peschke <mp3@de.ibm.com> wrote: >> need sched_clock for latency statistics > > sched_clock() probably isn't suitable for this application. It's a > scheduler thing and has a number of accuracy problems. > > But I thought we discussed this last time around? Maybe not.
I have been too obsessed with the other issues to remember.
> Maybe you've considered sched_clock()'s drawbacks and you've decided > they're all acceptable.
Admittedly, I didn't, but merely believed the comment above the function.
http://marc.theaimsgroup.com/?l=linux-kernel&m=114657675408686&w=2 sheds some light.
I would be happy to exploit an API that may result from that discussion. I would plead for exporting such an API to modules. I don't see how to implement statistics for latencies, otherwise.
Any other hints on how to replace my sched_clock() calls are welcome. (I want to measure elapsed times in units that are understandable to users without hardware manuals and calculator, such as milliseconds.)
Martin
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