kernel/linux.git/tools/perf/util/stat-shadow.c, branch v6.19.11

perf stat-shadow: In prepare_metric fix guard on reading NULL perf_stat_evsel

2026-03-04T12:19:30+00:00

[ Upstream commit 63b320aaac08ba267268ec21a195ce3c82dcb8ab ] The aggr value is setup to always be non-null creating a redundant guard for reading from it. Switch to using the perf_stat_evsel (ps) and narrow the scope of aggr so that it is known valid when used. Fixes: 3d65f6445fd93e3e ("perf stat-shadow: Read tool events directly") 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: Ian Rogers 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 Signed-off-by: Sasha Levin

perf stat: Ensure metrics are displayed even with failed events

2026-03-04T12:19:29+00:00

[ Upstream commit bb5a920b9099127915706fdd23eb540c9a69c338 ] Currently, `perf stat` skips or hides metrics when the underlying hardware events cannot be counted (e.g., due to insufficient permissions or unsupported events). In `--metric-only` mode, this often results in missing columns or blank spaces, making the output difficult to parse. Modify the logic to ensure metrics are consistently displayed by propagating NAN (Not a Number) through the expression evaluator. Specifically: 1. Update `prepare_metric()` in stat-shadow.c to treat uncounted events (where `run == 0`) as NAN. This leverages the existing math in expr.y to propagate NAN through metric expressions. 2. Remove the early return in the display logic's `printout()` function that was previously skipping metrics in `--metric-only` mode for failed events. l 3. Simplify `perf_stat__skip_metric_event()` to no longer depend on event runtime. Tested: 1. `perf all metrics test` did not crash while paranoid is 2. 2. Multiple combinations with `CPUs_utilized` while paranoid is 2. $ ./perf stat -M CPUs_utilized -a -- sleep 1 Performance counter stats for 'system wide': msec cpu-clock:u # nan CPUs CPUs_utilized 1,006,356,120 duration_time 1.004375550 seconds time elapsed $ ./perf stat -M CPUs_utilized -a -j -- sleep 1 {"counter-value" : "", "unit" : "msec", "event" : "cpu-clock:u", "event-runtime" : 0, "pcnt-running" : 100.00, "metric-value" : "nan", "metric-unit" : "CPUs CPUs_utilized"} {"counter-value" : "1006642462.000000", "unit" : "", "event" : "duration_time", "event-runtime" : 1, "pcnt-running" : 100.00} $ ./perf stat -M CPUs_utilized -a --metric-only -- sleep 1 Performance counter stats for 'system wide': CPUs CPUs_utilized nan 1.004424652 seconds time elapsed $ ./perf stat -M CPUs_utilized -a --metric-only -j -- sleep 1 {"CPUs CPUs_utilized" : "none"} Reviewed-by: Ian Rogers Signed-off-by: Chun-Tse Shao Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Yang Li Signed-off-by: Arnaldo Carvalho de Melo Stable-dep-of: 63b320aaac08 ("perf stat-shadow: In prepare_metric fix guard on reading NULL perf_stat_evsel") Signed-off-by: Sasha Levin

perf stat: Reduce scope of walltime_nsecs_stats

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

walltime_nsecs_stats is no longer used for counter values, move into that stat_config where it controls certain things like noise measurement. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf stat: Reduce scope of ru_stats

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

The ru_stats are used to capture user and system time stats when a process exits. These are then applied to user and system time tool events if their reads fail due to the process terminating. Reduce the scope now the metric code no longer reads these values. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf stat-shadow: Read tool events directly

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

When reading time values for metrics don't use the globals updated in builtin-stat, just read the events as regular events. The only exception is for time events where nanoseconds need converting to seconds as metrics assume time metrics are in seconds. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf auxtrace: Remove errno.h from auxtrace.h and fix transitive dependencies

2025-11-14T07:03:11+00:00

errno.h isn't used in auxtrace.h so remove it and fix build failures caused by transitive dependencies through auxtrace.h on errno.h. Signed-off-by: Ian Rogers Reviewed-by: James Clark 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 stat: Fix default metricgroup display on hybrid

2025-11-12T00:48:35+00:00

The logic to skip output of a default metric line was firing on Alderlake and not displaying 'TopdownL1 (cpu_atom)'. Remove the need_full_name check as it is equivalent to the different PMU test in the cases we care about, merge the 'if's and flip the evsel of the PMU test. The 'if' is now basically saying, if the output matches the last printed output then skip the output. Before: ``` TopdownL1 (cpu_core) # 11.3 % tma_bad_speculation # 24.3 % tma_frontend_bound TopdownL1 (cpu_core) # 33.9 % tma_backend_bound # 30.6 % tma_retiring # 42.2 % tma_backend_bound # 25.0 % tma_frontend_bound (49.81%) # 12.8 % tma_bad_speculation # 20.0 % tma_retiring (59.46%) ``` After: ``` TopdownL1 (cpu_core) # 8.3 % tma_bad_speculation # 43.7 % tma_frontend_bound # 30.7 % tma_backend_bound # 17.2 % tma_retiring TopdownL1 (cpu_atom) # 31.9 % tma_backend_bound # 37.6 % tma_frontend_bound (49.66%) # 18.0 % tma_bad_speculation # 12.6 % tma_retiring (59.58%) ``` Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf stat: Remove hard coded shadow metrics

2025-11-12T00:48:35+00:00

Now that the metrics are encoded in common json the hard coded printing means the metrics are shown twice. Remove the hard coded version. This means that when specifying events, and those events correspond to a hard coded metric, the metric will no longer be displayed. The metric will be displayed if the metric is requested. Due to the adhoc printing in the previous approach it was often found frustrating, the new approach avoids this. The default perf stat output on an alderlake now looks like: ``` $ perf stat -a -- sleep 1 Performance counter stats for 'system wide': 19,697 context-switches # nan cs/sec cs_per_second TopdownL1 (cpu_core) # 10.7 % tma_bad_speculation # 24.9 % tma_frontend_bound TopdownL1 (cpu_core) # 34.3 % tma_backend_bound # 30.1 % tma_retiring 6,593 page-faults # nan faults/sec page_faults_per_second 729,065,658 cpu_atom/cpu-cycles/ # nan GHz cycles_frequency (49.79%) 1,605,131,101 cpu_core/cpu-cycles/ # nan GHz cycles_frequency # 19.7 % tma_bad_speculation # 14.2 % tma_retiring (50.14%) # 37.3 % tma_frontend_bound (50.31%) 87,302,268 cpu_atom/branches/ # nan M/sec branch_frequency (60.27%) 512,046,956 cpu_core/branches/ # nan M/sec branch_frequency 1,111 cpu-migrations # nan migrations/sec migrations_per_second # 28.8 % tma_backend_bound (60.26%) 0.00 msec cpu-clock # 0.0 CPUs CPUs_utilized 392,509,323 cpu_atom/instructions/ # 0.6 instructions insn_per_cycle (60.19%) 2,990,369,310 cpu_core/instructions/ # 1.9 instructions insn_per_cycle 3,493,478 cpu_atom/branch-misses/ # 5.9 % branch_miss_rate (49.69%) 7,297,531 cpu_core/branch-misses/ # 1.4 % branch_miss_rate 1.006621701 seconds time elapsed ``` Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf jevents: Add metric DefaultShowEvents

2025-11-12T00:48:35+00:00

Some Default group metrics require their events showing for consistency with perf's previous behavior. Add a flag to indicate when this is the case and use it in stat-display. As events are coming from Default metrics remove that default hardware and software events from perf stat. Following this change the default perf stat output on an alderlake looks like: ``` $ perf stat -a -- sleep 1 Performance counter stats for 'system wide': 20,550 context-switches # nan cs/sec cs_per_second TopdownL1 (cpu_core) # 9.0 % tma_bad_speculation # 28.1 % tma_frontend_bound TopdownL1 (cpu_core) # 29.2 % tma_backend_bound # 33.7 % tma_retiring 6,685 page-faults # nan faults/sec page_faults_per_second 790,091,064 cpu_atom/cpu-cycles/ # nan GHz cycles_frequency (49.83%) 2,563,918,366 cpu_core/cpu-cycles/ # nan GHz cycles_frequency # 12.3 % tma_bad_speculation # 14.5 % tma_retiring (50.20%) # 33.8 % tma_frontend_bound (50.24%) 76,390,322 cpu_atom/branches/ # nan M/sec branch_frequency (60.20%) 1,015,173,047 cpu_core/branches/ # nan M/sec branch_frequency 1,325 cpu-migrations # nan migrations/sec migrations_per_second # 39.3 % tma_backend_bound (60.17%) 0.00 msec cpu-clock # 0.000 CPUs utilized # 0.0 CPUs CPUs_utilized 554,347,072 cpu_atom/instructions/ # 0.64 insn per cycle # 0.6 instructions insn_per_cycle (60.14%) 5,228,931,991 cpu_core/instructions/ # 2.04 insn per cycle # 2.0 instructions insn_per_cycle 4,308,874 cpu_atom/branch-misses/ # 5.65% of all branches # 5.6 % branch_miss_rate (49.76%) 9,890,606 cpu_core/branch-misses/ # 0.97% of all branches # 1.0 % branch_miss_rate 1.005477803 seconds time elapsed ``` Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim