From: Adrian Hunter <adrian.hunter@xxxxxxxxx> commit 5501e9229a80d95a1ea68609f44c447a75d23ed5 upstream. In some cases, the number of cpus (nr_cpus_online) is confused with the maximum cpu number (nr_cpus_avail), which results in the error in the example below: Example on system with 8 cpus: Before: # echo 0 > /sys/devices/system/cpu/cpu2/online # ./perf record --kcore -e intel_pt// taskset --cpu-list 7 uname Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.147 MB perf.data ] # ./perf script --itrace=e Requested CPU 7 too large. Consider raising MAX_NR_CPUS 0x25908 [0x8]: failed to process type: 68 [Invalid argument] After: # ./perf script --itrace=e # Fixes: 8c7274691f0d ("perf machine: Replace MAX_NR_CPUS with perf_env::nr_cpus_online") Fixes: 7df4e36a4785 ("perf session: Replace MAX_NR_CPUS with perf_env::nr_cpus_online") Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Tested-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: http://lore.kernel.org/lkml/20210107174159.24897-1-adrian.hunter@xxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/perf/util/machine.c | 4 ++-- tools/perf/util/session.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -2973,7 +2973,7 @@ int machines__for_each_thread(struct mac pid_t machine__get_current_tid(struct machine *machine, int cpu) { - int nr_cpus = min(machine->env->nr_cpus_online, MAX_NR_CPUS); + int nr_cpus = min(machine->env->nr_cpus_avail, MAX_NR_CPUS); if (cpu < 0 || cpu >= nr_cpus || !machine->current_tid) return -1; @@ -2985,7 +2985,7 @@ int machine__set_current_tid(struct mach pid_t tid) { struct thread *thread; - int nr_cpus = min(machine->env->nr_cpus_online, MAX_NR_CPUS); + int nr_cpus = min(machine->env->nr_cpus_avail, MAX_NR_CPUS); if (cpu < 0) return -EINVAL; --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -2397,7 +2397,7 @@ int perf_session__cpu_bitmap(struct perf { int i, err = -1; struct perf_cpu_map *map; - int nr_cpus = min(session->header.env.nr_cpus_online, MAX_NR_CPUS); + int nr_cpus = min(session->header.env.nr_cpus_avail, MAX_NR_CPUS); for (i = 0; i < PERF_TYPE_MAX; ++i) { struct evsel *evsel;