Re: [RFC] [Patch 7/8] statistics infrastructure - exploitation prerequisite

From: Martin Peschke
Date: Tue May 16 2006 - 18:35:50 EST

Andrew Morton wrote:
Martin Peschke <mp3@xxxxxxxxxx> 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.
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.)


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