Hi, On Fri, Mar 18, 2011 at 8:55 AM, 陳韋任 <che...@iis.sinica.edu.tw> wrote: > Hi, all > > I am interested in the LBR (Last Branch Record), and > I saw perfmon supports LBR for Intel Core i7. > Yes, it does on select processors.
> http://perfmon2.sourceforge.net/pfmon_intel_corei7.html > > How the LBR is used in perfmon? I cannot find anything about > LBR from the output of `pfmon -l`. Or LBR only can be used > by using libpfm3? > LBR is not an event. It is a HW feature of the PMU that collect taken branches. It is used in sampling mode. It give you the last N branches which led to the basic block where your sampling event occurred. Use pfmon -h to find out more about pfmon support for LBR. It is available on Nehalem/Westmere processors primarily. > The version of perfmon kernel interface is 2.9, and the one > of pfmon is 3.8. > Please use the latest source code for full LBR support. Pull libpfm3 from CVS. Pull the latest kernel from the GIT tree. > I also note that there are disscussions about adding LBR > support into perf_events. Like, > > http://thread.gmane.org/gmane.comp.linux.perfmon2.devel/2026 > > Does anyone know how it is going? Does libpfm4 support LBR? > Perf_events in using LBR internally in support of PEBS (to correct the off-by-one skid of the PEBS instruction address) but as of today, it is not yet exposed to users. But patches have been proposed. > Thanks! > > Regards, > chenwj > > -- > Wei-Ren Chen (陳韋任) > Parallel Processing Lab, Institute of Information Science, > Academia Sinica, Taiwan (R.O.C.) > Tel:886-2-2788-3799 #1667 > > ------------------------------------------------------------------------------ > Colocation vs. Managed Hosting > A question and answer guide to determining the best fit > for your organization - today and in the future. > http://p.sf.net/sfu/internap-sfd2d > _______________________________________________ > perfmon2-devel mailing list > perfmon2-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/perfmon2-devel > ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
