kernel/linux.git/tools/perf/util/tool_pmu.c, branch v7.1

Revert "perf tool_pmu: More accurately set the cpus for tool events"

2026-02-10T12:32:34+00:00

This reverts commit d8d8a0b3603a9a8fa207cf9e4f292e81dc5d1008. The setting of a user CPU map can cause an empty intersection when combined with CPU 0 and the event removed. This later triggers a segv in the stat-shadow logic. Let's put back a full online CPU map for now by reverting this patch. Closes: https://lore.kernel.org/linux-perf-users/cgja46br2smmznxs7kbeabs6zgv3b4olfqgh2fdp5mxk2yom4v@w6jjgov6hdi6/ Reported-by: Andres Freund Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Dapeng Mi Cc: Dr. David Alan Gilbert Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Falcon Cc: Thomas Richter Cc: Yang Li Signed-off-by: Arnaldo Carvalho de Melo

perf tool_pmu: More accurately set the cpus for tool events

2025-11-18T02:43:09+00:00

The user and system time events can record on different CPUs, but for all other events a single CPU map of just CPU 0 makes sense. In parse-events detect a tool PMU and then pass the perf_event_attr so that the tool_pmu can return CPUs specific for the event. This avoids a CPU map of all online CPUs being used for events like duration_time. Avoiding this avoids the evlist CPUs containing CPUs for which duration_time just gives 0. Minimizing the evlist CPUs can remove unnecessary sched_setaffinity syscalls that delay metric calculations. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf tool_pmu: Use old_count when computing count values for time events

2025-11-18T02:43:08+00:00

When running in interval mode every third count of a time event isn't showing properly: ``` $ perf stat -e duration_time -a -I 1000 1.001082862 1,002,290,425 duration_time 2.004264262 1,003,183,516 duration_time 3.007381401 duration_time 4.011160141 1,003,705,631 duration_time 5.014515385 1,003,290,110 duration_time 6.018539680 duration_time 7.022065321 1,003,591,720 duration_time ``` The regression came in with a different fix, found through bisection, commit 68cb1567439f ("perf tool_pmu: Fix aggregation on duration_time"). The issue is caused by the enabled and running time of the event matching the old_count's and creating a delta of 0, which is indicative of an error. Fixes: 68cb1567439f ("perf tool_pmu: Fix aggregation on duration_time") Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf tool_pmu: Make core_wide and target_cpu json events

2025-11-12T00:48:36+00:00

For the sake of better documentation, add core_wide and target_cpu to the tool.json. When the values of system_wide and user_requested_cpu_list are unknown, use the values from the global stat_config. Example output showing how '-a' modifies the values in `perf stat`: ``` $ perf stat -e core_wide,target_cpu true Performance counter stats for 'true': 0 core_wide 0 target_cpu 0.000993787 seconds time elapsed 0.001128000 seconds user 0.000000000 seconds sys $ perf stat -e core_wide,target_cpu -a true Performance counter stats for 'system wide': 1 core_wide 1 target_cpu 0.002271723 seconds time elapsed $ perf list ... tool: core_wide [1 if not SMT,if SMT are events being gathered on all SMT threads 1 otherwise 0. Unit: tool] ... target_cpu [1 if CPUs being analyzed,0 if threads/processes. Unit: tool] ... ``` Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf tools: Remove a pointless check

2025-09-19T15:14:30+00:00

Static analyser cppcheck says: linux-6.16/tools/perf/util/tool_pmu.c:242:15: warning: Opposite inner 'if' condition leads to a dead code block. [oppositeInnerCondition] Source code is: for (thread = 0; thread < nthreads; thread++) { if (thread >= nthreads) break; Reported-by: David Binderman Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

libperf evsel: Rename own_cpus to pmu_cpus

2025-07-24T20:41:35+00:00

own_cpus is generally the cpumask from the PMU. Rename to pmu_cpus to try to make this clearer. Variable rename with no other changes. Reviewed-by: Thomas Falcon Signed-off-by: Ian Rogers Tested-by: James Clark Link: https://lore.kernel.org/r/20250719030517.1990983-7-irogers@google.com Signed-off-by: Namhyung Kim

perf tool_pmu: Allow num_cpus(_online) to be specific to a cpumask

2025-07-24T20:41:35+00:00

For hybrid metrics it is useful to know the number of p-core or e-core CPUs. If a cpumask is specified for the num_cpus or num_cpus_online tool events, compute the value relative to the given mask rather than for the full system. ``` $ sudo /tmp/perf/perf stat -e 'tool/num_cpus/,tool/num_cpus,cpu=cpu_core/, tool/num_cpus,cpu=cpu_atom/,tool/num_cpus_online/,tool/num_cpus_online, cpu=cpu_core/,tool/num_cpus_online,cpu=cpu_atom/' true Performance counter stats for 'true': 28 tool/num_cpus/ 16 tool/num_cpus,cpu=cpu_core/ 12 tool/num_cpus,cpu=cpu_atom/ 28 tool/num_cpus_online/ 16 tool/num_cpus_online,cpu=cpu_core/ 12 tool/num_cpus_online,cpu=cpu_atom/ 0.000767205 seconds time elapsed 0.000938000 seconds user 0.000000000 seconds sys ``` Reviewed-by: Thomas Falcon Signed-off-by: Ian Rogers Tested-by: James Clark Link: https://lore.kernel.org/r/20250719030517.1990983-6-irogers@google.com Signed-off-by: Namhyung Kim

perf pmu: Change aliases from list to hashmap

2025-05-13T19:36:43+00:00

Finding an alias for things like perf_pmu__have_event() would need to search the aliases list, whilst this happens relatively infrequently it can be a significant overhead in testing. Switch to using a hashmap. Move common initialization code to perf_pmu__init(). Refactor the test 'struct perf_pmu_test_pmu' to not have perf pmu within it to better support the perf_pmu__init() function. Before: ``` $ time perf test "Parsing of PMU event table metrics" 10.3: Parsing of PMU event table metrics : Ok 10.4: Parsing of PMU event table metrics with fake PMUs : Ok real 0m13.287s user 0m13.026s sys 0m0.532s ``` After: ``` $ time perf test "Parsing of PMU event table metrics" 10.3: Parsing of PMU event table metrics : Ok 10.4: Parsing of PMU event table metrics with fake PMUs : Ok real 0m13.011s user 0m12.885s sys 0m0.485s ``` Committer testing: root@number:~# grep -m1 'model name' /proc/cpuinfo model name : AMD Ryzen 9 9950X3D 16-Core Processor root@number:~# Before: root@number:~# time perf test "Parsing of PMU event table metrics" 10.3: Parsing of PMU event table metrics : Ok 10.4: Parsing of PMU event table metrics with fake PMUs : Ok real 0m9.296s user 0m9.361s sys 0m0.063s root@number:~# After: root@number:~# time perf test "Parsing of PMU event table metrics" 10.3: Parsing of PMU event table metrics : Ok 10.4: Parsing of PMU event table metrics with fake PMUs : Ok real 0m9.286s user 0m9.354s sys 0m0.062s root@number:~# Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Tested-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Thomas Richter Cc: Xu Yang Link: https://lore.kernel.org/r/20250512194622.33258-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tool_pmu: Fix aggregation on duration_time

2025-04-25T15:32:04+00:00

evsel__count_has_error() fails counters when the enabled or running time are 0. The duration_time event reads 0 when the cpu_map_idx != 0 to avoid aggregating time over CPUs. Change the enable and running time to always have a ratio of 100% so that evsel__count_has_error won't fail. Before: ``` $ sudo /tmp/perf/perf stat --per-core -a -M UNCORE_FREQ sleep 1 Performance counter stats for 'system wide': S0-D0-C0 1 2,615,819,485 UNC_CLOCK.SOCKET # 2.61 UNCORE_FREQ S0-D0-C0 2 duration_time 1.002111784 seconds time elapsed ``` After: ``` $ perf stat --per-core -a -M UNCORE_FREQ sleep 1 Performance counter stats for 'system wide': S0-D0-C0 1 758,160,296 UNC_CLOCK.SOCKET # 0.76 UNCORE_FREQ S0-D0-C0 2 1,003,438,246 duration_time 1.002486017 seconds time elapsed ``` Note: the metric reads the value a different way and isn't impacted. Fixes: 240505b2d0adcdc8 ("perf tool_pmu: Factor tool events into their own PMU") Reported-by: Stephane Eranian Reviewed-by: James Clark Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Richter Link: https://lore.kernel.org/r/20250423050358.94310-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Handle memory failure in tool_pmu__new()

2025-03-20T00:00:16+00:00

On linux-next commit 72c6f57a4193 ("perf pmu: Dynamically allocate tool PMU") allocated PMU named "tool" dynamicly. However that allocation can fail and a NULL pointer is returned. That case is currently not handled and would result in an invalid address reference. Add a check for NULL pointer. Fixes: 72c6f57a4193 ("perf pmu: Dynamically allocate tool PMU") Signed-off-by: Thomas Richter Reviewed-by: James Clark Link: https://lore.kernel.org/r/20250319122820.2898333-1-tmricht@linux.ibm.com Signed-off-by: Namhyung Kim