aboutsummaryrefslogtreecommitdiffstats
path: root/tools/perf/util/header.c
diff options
context:
space:
mode:
authorKan Liang <kan.liang@linux.intel.com>2020-02-28 08:30:01 -0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-03-09 21:43:24 -0300
commitd3f85437ad6a55113882d730beaa75759452da8f (patch)
tree1aa5ddc57164d59d2e71482cc5669e258a9273ab /tools/perf/util/header.c
parentperf tools: Add hw_idx in struct branch_stack (diff)
downloadlinux-dev-d3f85437ad6a55113882d730beaa75759452da8f.tar.xz
linux-dev-d3f85437ad6a55113882d730beaa75759452da8f.zip
perf evsel: Support PERF_SAMPLE_BRANCH_HW_INDEX
A new branch sample type PERF_SAMPLE_BRANCH_HW_INDEX has been introduced in latest kernel. Enable HW_INDEX by default in LBR call stack mode. If kernel doesn't support the sample type, switching it off. Add HW_INDEX in attr_fprintf as well. User can check whether the branch sample type is set via debug information or header. Committer testing: First collect some samples with LBR callchains, system wide, for a few seconds: # perf record --call-graph lbr -a sleep 5 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.625 MB perf.data (224 samples) ] # Now lets use 'perf evlist -v' to look at the branch_sample_type: # perf evlist -v cycles: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|BRANCH_STACK, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: USER|CALL_STACK|NO_FLAGS|NO_CYCLES|HW_INDEX # So the machine has the kernel feature, and it was correctly added to perf_event_attr.branch_sample_type, for the default 'cycles' event. If we do it in another machine, where the kernel lacks the HW_INDEX feature, we get: # perf record --call-graph lbr -a sleep 2s [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.690 MB perf.data (499 samples) ] # perf evlist -v cycles: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|BRANCH_STACK, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: USER|CALL_STACK|NO_FLAGS|NO_CYCLES # No HW_INDEX in attr.branch_sample_type. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pavel Gerasimov <pavel.gerasimov@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com> Link: http://lore.kernel.org/lkml/20200228163011.19358-3-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/header.c')
0 files changed, 0 insertions, 0 deletions