Re: [PATCH] perf intel-pt: Fix 'CPU too large' error

[Arnaldo Carvalho de Melo]

Em Thu, Jan 07, 2021 at 03:46:03PM -0500, Liang, Kan escreveu:
> 
> 
> On 1/7/2021 12:41 PM, Adrian Hunter wrote:
> > 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")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> 
> 
> Tested-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

Thanks, applied.

- Arnaldo

 
> Thanks,
> Kan
> 
> > ---
> >   tools/perf/util/machine.c | 4 ++--
> >   tools/perf/util/session.c | 2 +-
> >   2 files changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> > index 1ae32a81639c..46844599d25d 100644
> > --- a/tools/perf/util/machine.c
> > +++ b/tools/perf/util/machine.c
> > @@ -2977,7 +2977,7 @@ int machines__for_each_thread(struct machines *machines,
> >   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;
> > @@ -2989,7 +2989,7 @@ int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
> >   			     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;
> > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> > index 3b3c50b12791..2777c2df7d87 100644
> > --- a/tools/perf/util/session.c
> > +++ b/tools/perf/util/session.c
> > @@ -2391,7 +2391,7 @@ int perf_session__cpu_bitmap(struct perf_session *session,
> >   {
> >   	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;
> > 

-- 

- Arnaldo