perf metric: Encode and use metric-id as qualifier
For a metric like IPC a group of events like {instructions,cycles}:W would be formed. If the events names were changed in parsing then the metric expression parser would fail to find them. This change makes the event encoding be something like: {instructions/metric-id=instructions/, cycles/metric-id=cycles/} and then uses the evsel's stable metric-id value to locate the events. This fixes the case that an event is restricted to user because of the paranoia setting: $ echo 2 > /proc/sys/kernel/perf_event_paranoid $ perf stat -M IPC /bin/true Performance counter stats for '/bin/true': 150,298 inst_retired.any:u # 0.77 IPC 187,095 cpu_clk_unhalted.thread:u 0.002042731 seconds time elapsed 0.000000000 seconds user 0.002377000 seconds sys Adding the metric-id as a qualifier has a complication in that qualifiers will become embedded in qualifiers. For example, msr/tsc/ could become msr/tsc,metric-id=msr/tsc// which will fail parse-events. To solve this problem the metric is encoded and decoded for the metric-id with !<num> standing in for an encoded value. Previously ! wasn't parsed. With this msr/tsc/ becomes msr/tsc,metric-id=msr!3tsc!3/ The metric expression parser is changed so that @ isn't changed to /, instead this is done when the ID is encoded for parse events. metricgroup__add_metric_non_group() and metricgroup__add_metric_weak_group() need to inject the metric-id qualifier, so to avoid repetition they are merged into a single metricgroup__build_event_string with error codes more rigorously checked. stat-shadow's prepare_metric() uses the metric-id to match the metricgroup code. As "metric-id=..." is added to all events, it is adding during testing with the fake PMU. This complicates pmu_str_check code as PE_PMU_EVENT_FAKE won't match as part of a configuration. The testing fake PMU case is fixed so that if a known qualifier with an ! is parsed then it isn't reported as a fake PMU. This is sufficient to pass all testing but it and the original mechanism are somewhat brittle. Signed-off-by:Ian Rogers <irogers@google.com> Acked-by:
Andi Kleen <ak@linux.intel.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Antonov <alexander.antonov@linux.intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Kilroy <andrew.kilroy@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Changbin Du <changbin.du@intel.com> Cc: Denys Zagorui <dzagorui@cisco.com> Cc: Fabian Hemmer <copy@copy.sh> Cc: Felix Fietkau <nbd@nbd.name> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jacob Keller <jacob.e.keller@intel.com> Cc: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joakim Zhang <qiangqing.zhang@nxp.com> Cc: John Garry <john.garry@huawei.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Kees Kook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nicholas Fraser <nfraser@codeweavers.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Paul Clarke <pc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: ShihCheng Tu <mrtoastcheng@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Wan Jiabing <wanjiabing@vivo.com> Cc: Zhen Lei <thunder.leizhen@huawei.com> Link: https://lore.kernel.org/r/20211015172132.1162559-17-irogers@google.com Signed-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
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