I am having a problem while using libpfm-4.4.0, which I think related to this question. What I see is that the number of instructions retired drops significantly if I add a few more events to the list of monitored events in my program. I suspect that the added events conflict with the existing ones, hence brings the actual count down. Do you have the same thoughts? Also, could you point me to where I can find information about these conflicting events in order to configure them correctly? How can I know how many performance counters that my CPU has?
Thanks, Binh On 07/23/2013 02:22 AM, Stephane Eranian wrote: > Hi, > > On Tue, Jul 23, 2013 at 2:25 AM, Leonardo Piga <leonardo.p...@gmail.com> > wrote: >> Hello, >> >> I am trying to measure some performance counters on Ivy Bridge, which has 4 >> PCM. I would like to know if there is a way to group up counters so that I >> can measure events on the same time. >> >> For example, I need to measure 8 counters (e.g., A,B,C,D,E,F,G,H). And I >> would like to sample A,B,C,D together and E,F,G,H together. >> >> How can I do this using libpfm? I saw that task.c on perf_examples has a way >> to group up counters, but I couldn't use it. >> > task -e A,B,C,D -e E,F,G,H ..... > > Of course in each group, events have to be compatible with each other. > That means they cannot conflict on a counter. If so then, try moving the > conflicting events to separate groups. > > Also a group cannot have more events than there are counters. > Note that by default the NMI watchdog uses one counter and runs > all the time unless you disable it via /proc/sys/kernel/nmi_watchdog. > >> Thank you for any help, >> >> -- >> Leonardo >> >> ------------------------------------------------------------------------------ >> See everything from the browser to the database with AppDynamics >> Get end-to-end visibility with application monitoring from AppDynamics >> Isolate bottlenecks and diagnose root cause in seconds. >> Start your free trial of AppDynamics Pro today! >> http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk >> _______________________________________________ >> perfmon2-devel mailing list >> perfmon2-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/perfmon2-devel >> > ------------------------------------------------------------------------------ > See everything from the browser to the database with AppDynamics > Get end-to-end visibility with application monitoring from AppDynamics > Isolate bottlenecks and diagnose root cause in seconds. > Start your free trial of AppDynamics Pro today! > http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk > _______________________________________________ > perfmon2-devel mailing list > perfmon2-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/perfmon2-devel -- -Binh ------------------------------------------------------------------------------ Sponsored by Intel(R) XDK Develop, test and display web and hybrid apps with a single code base. Download it for free now! http://pubads.g.doubleclick.net/gampad/clk?id=111408631&iu=/4140/ostg.clktrk _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
