On 11/03/2015 11:01 PM, Stephane Eranian wrote: > Will, > > On Tue, Nov 3, 2015 at 10:12 PM, William Cohen <wco...@redhat.com > <mailto:wco...@redhat.com>> wrote: > > On 11/03/2015 01:41 PM, Stephane Eranian wrote: > > Will, > > > > Could you provide the list of events detected by libpfm4? > > You need to run as root: sudo examples/showevtinfo -L > > Clearly the ubo uncore event should not be processed as part of > tracepoints. > > Hi Stephane, > > The count of the number of elements in the array was not be reset when > the static array was being reset. Attached is a patch that addresses the > problem. It allows the PAPI fmultiplex1 test to run correctly when the > tracepoints are being read in multiple times. > > I don't understand why this patch fixes the problem. perf_nevents > (perf_event_support.pme_count) > is statically initialized. By the time you get to pfm_perf_init() it still > holds that initial value which is > what you are setting it. Why would that help? > > > -Will > >
Hi Stephane, In the papi fmultiplex1.F test the initialization is being done multiple times. The initialization sets perf_pe to perf_static_events. However, when the test is run as root the array is cloned and the number of entries in the array is increased. The pme_count field in perf_event_support is changed when the additional tracepoints are added to the cloned array. The changes in the pme_count are caused by the "perf_nevents++" in the code. It is kind of hidden by the perf_nevents macro. You can see the changes to pme_count in gdb with a hardware watch point with the following gdb command: watch perf_event_support.pme_count When done the pme_count field no longer has the original count of elements in perf_static_events. If the initialization is run again without this patch, the number of entries in the array is listed number of entries in the static array AND the tracepoint entries. The cloning process for the reinitialization gets things very wrong copying past the end of the perf_static_events array and the test crashes. The supplied patch ensures that if the initialization is run multiple times that it will get the correct number of entries in the static array. This problem may not have been noticeable because it only occurs when the initialization is being done as root and the initialization is being done multiple times. -Will ------------------------------------------------------------------------------ _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
