Hi,

I may not be the best one to answer: I use oprofile with regular wake-up and I 
am testing on long enough use cases so that a wake-up every scheduler tick is 
sufficient (like "top", it converges in some seconds to the right values).
I don't really have use of performance counter wake-ups and I don't really know 
what CPU_CYCLES perf counter will bring except more granularity. Maybe 
something related to Idle time where timer-based oprofile would not execute as 
we can be tickless.
I could be more interested in more granularity of timer based solution but 
official guideline may be to use CPU_CYCLES ;-)

So guys, please speak out if you need perf counters in oprofile, if you want 
more granularity in wake-ups. Or even simply require this interruption from 
perf counters for other purposes.

Regards
Fred

Frederic Turgis
OMAP Platform Business Unit - OMAP System Engineering - Platform Enablement



Texas Instruments France SA, 821 Avenue Jack Kilby, 06270 Villeneuve Loubet. 
036 420 040 R.C.S Antibes. Capital de EUR 753.920



________________________________

From: David Long [mailto:dave.l...@linaro.org]
Sent: Monday, September 26, 2011 7:27 AM
To: Turgis, Frederic
Cc: Bianconi, Cyril; linaro-dev@lists.linaro.org; Michael Hope; Avik Sil; Dave 
Martin; Christian Robottom Reis; andy.gr...@linaro.org
Subject: RE: 11.07 oprofile on panda busted?

Andy made an interesting suggestion to me.  What if the profile event code 
allocated all the counters to the requested event.  It could reallocate half of 
them if a second event was also requested, and so on, till we're down to one 
(unreliably interrupting) counter.  Or we could set a limit requiring at least 
three counters per event.

The problem would still exist, but this should throw the maximum amount of 
ammunition we have towards minimizing it.  Would this be worth the effort to 
implement?

-dl

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