On Mon, Aug 9, 2010 at 8:41 PM, Kristen Walcott <kr...@cs.virginia.edu> wrote: > Hi, > I'm trying to modify the sample period during test execution (after > perf_event_open has been called) from code similar to pebs_smpl. I would > like to do it based on certain conditions as the samples are read in. Is > there a simple way to do this? For that, you need the user level to get notified on each sample. That is possible with perf_events. Take a look at notify_self.c for an example on how to set this up. As for updating the sampling period you can do this via ioctl(fd, PERF_EVENT_IOC_PERIOD, new_period)
> I saw in kernel/perf_event.c that there is a perf_adjust_period function, > but I couldn't find anything similar at the user level. Yes, but that's for something else. perf_events supports a rate and fixed period sampling mode. I recommend using fixed period. > Thanks for the help > - Kristen > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by > > Make an app they can't live without > Enter the BlackBerry Developer Challenge > http://p.sf.net/sfu/RIM-dev2dev > _______________________________________________ > perfmon2-devel mailing list > perfmon2-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/perfmon2-devel > > ------------------------------------------------------------------------------ This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
