Hi Stephane, One of the issues I ran into with the Power6 port of perfmon2, which hasn't been resolved (I forgot about it :( ), is that pfm_dispatch_events doesn't give the function enough information to choose the correct group in some cases. What's missing is whether or not the caller is going to want to set PFM_REGFL_OVFL_NOTIFY on a particular event. In the case of Power6, this is a problem because pfm_dispatch_events may choose a group in which one or two of the events are mapped to counters which do not interrupt on overflow - counters 5 & 6.
There's an error in the current implementation that we ignore the PFM_REGFL_OVFL_NOTIFY flag for counters 5 & 6 when it comes to the pfm_write_pmds call. If the implementation were [more] correct, we would reject a call to write counters 5 or 6 with that flag set. The code that implements PFM_REGFL_OVFL_NOTIFY is in perfmon_rw.c and is not accessible to arch-specific code (from what I can tell). To fix this, we'd have to insert some new arch-independent code. However, even this would not be a good solution, because the caller, ideally, should be informed at the time of the pfm_dispatch_events call that perfmon would be unable to support their overflow notify request. And, actually, in some cases, if pfm_dispatch_events knew that overflow was going to be needed on these two events, it might be able to find another group with these same events, but counted on counters that support interrupt on overflow. In the structure, pfmlib_event_t, there is a "flags" field provided. It isn't described in the man page for pfm_dispatch_events. Would it make sense for this flags field to take PFM_REGFL_OVFL_NOTIFY as one of its flag values? Or would a better place be to add a Power-specific mod_in structure? Thanks for your consideration, - Corey Corey Ashford Software Engineer IBM Linux Technology Center, Linux Toolchain Beaverton, OR 503-578-3507 [EMAIL PROTECTED] ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ perfmon2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
