1 Commits

Author	SHA1	Message	Date
Thomas Richter	b96e6615cd	perf auxtrace: Support for perf report -D for s390 ... Add initial support for s390 auxiliary traces using the CPU-Measurement Sampling Facility. Support and ignore PERF_REPORT_AUXTRACE_INFO records in the perf data file. Later patches will show the contents of the auxiliary traces. Setup the auxtrace queues and data structures for s390. A raw dump of the perf.data file now does not show an error when an auxtrace event is encountered. Output before: [root@s35lp76 perf]# ./perf report -D -i perf.data.auxtrace 0x128 [0x10]: failed to process type: 70 Error: failed to process sample 0x128 [0x10]: event: 70 . . ... raw event: size 16 bytes . 0000: 00 00 00 46 00 00 00 10 00 00 00 00 00 00 00 00 ...F............ 0x128 [0x10]: PERF_RECORD_AUXTRACE_INFO type: 0 [root@s35lp76 perf]# Output after: # ./perf report -D -i perf.data.auxtrace |fgrep PERF_RECORD_AUXTRACE 0 0 0x128 [0x10]: PERF_RECORD_AUXTRACE_INFO type: 5 0 0 0x25a66 [0x30]: PERF_RECORD_AUXTRACE size: 0x40000 offset: 0 ref: 0 idx: 4 tid: -1 cpu: 4 .... Additional notes about the underlying hardware and software implementation, provided by Hendrik Brueckner (see Link: below). ============================================================================= The CPU-Measurement Facility (CPU-MF) provides a set of functions to obtain performance information on the mainframe. Basically, it was introduced with System z10 years ago for the z/Architecture, that means, 64-bit. For Linux, there are two facilities of interest, counter facility and sampling facility. The counter facility provides hardware counters for instructions, cycles, crypto-activities, and many more. The sampling facility is a hardware sampler that when started will write samples at a particular interval into a sampling buffer. At some point, for example, if a sample block is full, it generates an interrupt to collect samples (while the sampler continues to run). Few years ago, I started to provide the a perf PMU to use the counter and sampling facilities. Recently, the device driver was updated to also "export" the sampling buffer into the AUX area. Thomas now completed the related perf work to interpret and process these AUX data. If people are more interested in the sampling facility, they can have a look into: - The Load-Program-Parameter and the CPU-Measurement Facilities, SA23-2260-05 http://www-01.ibm.com/support/docview.wss?uid=isg26fcd1cc32246f4c8852574ce0044734a and to learn how-to use it for Linux on Z, have look at chapter 54, "Using the CPU-measurement facilities" in the: - Device Drivers, Features, and Commands, SC33-8411-34 http://public.dhe.ibm.com/software/dw/linux390/docu/l416dd34.pdf ============================================================================= Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Link: http://lkml.kernel.org/r/20180803100758.GA28475@linux.ibm.com Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Link: http://lkml.kernel.org/r/20180802074622.13641-2-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>	2018-08-03 10:34:18 -03:00