Hello Ivo -- Yep, you will need to use the AMD IBS feature.
Sampling the performance monitoring counters (PMCs) is imprecise. When a PMC (overflow) generates an interrupt, the processing pipeline is most probably far beyond the actual instruction which caused the PMC (overflow) that triggers the sampling interrupt. Thus, it's not possible to capture the data operand address for instructions that access memory via PMC sampling. IBS has this capability. After the IBS hardware selects and tags an execution op for sampling, it records the precise IP and events for the op. The IP is the address of the parent x86 op. If the op is a load or store, the data operand address is captured, too. Robert is the right guy for software questions. (I'm doing hardware now. :-) -- pj Paul Drongowski Consultant at AMD -----Original Message----- From: Ivo Steinmann [mailto:isteinm...@bluewin.ch] Sent: Sunday, June 05, 2011 7:44 PM To: perfmon2-devel@lists.sourceforge.net Subject: [perfmon2] AMD IBS Support Hello all I'm really new to all this performance monitoring stuff. I would like to monitor cache accesses on my amd64 phenom and opteron machine and I also would like to get the address that is accessed. So I tried DATA_CACHE_ACCESSES, REQUESTS_TO_L2, READ_REQUEST_TO_L3_CACHE. It's working so far as the events are raised (using sigaction mechanism). attr.wakeup_events = 1; attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; //| PERF_SAMPLE_READ | PERF_SAMPLE_PERIOD; attr.sample_period = SMPL_PERIOD; attr.read_format = 0;//PERF_FORMAT_GROUP | PERF_FORMAT_ID | PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING; But somehow the addr is allways zero (nil) :( I think I have to use the amd64 IBS stuff (I guess then an address is returned). I found this thread: http://lkml.org/lkml/2010/4/13/336 from Robert Richter. There he provides some patches for amd64 ibs support. And here an example for libpfm4: https://lkml.org/lkml/2010/10/18/329 Are this patches obsolete? How can I use IBS with libpfm4? I'm using this kernel version: git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile.git And libpfm4 from: git://perfmon2.git.sourceforge.net/gitroot/perfmon2/libpfm4 Thx Ivo Steinmann ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
