Re: [RFC] perf: need to expose sched_clock to correlate usersamples with kernel samples

[Pawel Moll]

On Thu, 2013-04-04 at 08:37 +0100, Richard Cochran wrote:
> > I get the reasoning around reusing the fd we already have, but is
> > the possibility of a dynamic chardev pathname really a big concern?
> 
> I have been following this thread, and, not knowing very much about
> perf, I would think that the userland can easily open a second file
> (the dynamic posix clock chardev) in order to get these time stamps.

Sure it can - I've tested it. It's just a bit cumbersome in my opinion
(there is nothing else perf-related in /dev). I can agree to disagree if
you think otherwise :-)

> > Maybe can we extend the dynamic posix clock code to work on more
> > then just the chardev? Although I worry about multiplexing too much
> > functionality on the file.
> 
> I don't yet see a need for that, but if we do, then it should work in
> a generic way, and not as a list of special cases, like we saw in the
> patch.

By all means - and even more generic way than it is now (why character
devices not any other file?). I'll give it a try.

PaweÅ



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