Re: profiling aufs

On Mon, 2002-10-07 at 20:34, Henrik Nordstrom wrote:
> On Monday 07 October 2002 11.00, Robert Collins wrote:
>
> > This isn't true. IFF the worker threads do not use -any- common
> > profiled calls, then it works, otherwise we may get xmalloc timings
> > trashed (for example).
>
> xmalloc isn't exacly threads safe today if any of the
> trace/debug/leakcheck xmalloc options is enabled..

Yeah, and this is a minor problem.
 
> And I agree that having "threads safe" profiling is a good idea and
> needs to be investigated. I think a good start would be to allow for
> separate profiling timers. Having a full profiling block per therad
> is most likely overkill.

Probably, but the overhead is relatively small, and it seemed simpler to
simply use a consistent struct across the board.

> A interesting question is how to perform any
> meaningful statisticts on per-thread timers.. the actual timer itself
> is only a small part, you also need a readout of the timer.

I believe I already addressed this. Unless we are interested in the
performance within each thread (I don't think we are), we can simply
collate the statistics each profile event.

Rob