[PerfSuite-users] Updates to earlier issues

[Rick K. <rk...@nc...>]

Updates on some outstanding issues/questions:

Regarding the following message that was sent back in January, I thought I 
would say that the new example program mentioned in the last paragraph 
has been included in the new 0.6.2a3 distribution.  It's called "sampler" 
and it can be found in the directory "examples/sampler", which will be 
installed under $PREFIX/share/perfsuite.

Also, the environment variable PSPROCESS_MAPPER, which was introduced to 
address psprocess issues that were raised by Tirath Ramdas around the same 
time, is now available in the 0.6.2a3 release.  The thread originally
describing this can be found here:

http://sourceforge.net/mailarchive/forum.php?thread_id=9490386&forum_id=39162

Rick

On Mon, 30 Jan 2006, Rick Kufrin wrote:

> Tirath,
>
>> Thanks for clarifying that for me; for some reason I had the idea
>> that the interrupt is triggered every \tau seconds, at which point it
>> samples the counter, then resets it, then goes back to sleep for
>> another \tau seconds, repeat... in which case the total count in the
>> end should have been the aggregate count.
>
> Well, that's not a bad idea but it's not the way it's implemented in
> PerfSuite.  I should say this is a limitation of PerfSuite, not the
> hardware or driver support - there's nothing to prevent one from
> configuring on, say, the Itanium2, one performance counter to generate
> an interrupt after some number of events (whether cycles or whatever),
> and use that as a trigger to read event counts from one of the other 3
> counters on that CPU.  This could provide some type of real-time
> monitoring I think.
>
> There will be a new example program available that does something similar
> but using interval timers (setitimer) to generate periodic interrupts,
> allowing the interrupt handler to read the current value of the counters.
> I'm thinking this is similar to what you're describing.
>
> Rick