Messages in this thread | | | From | Ian Rogers <> | Date | Tue, 7 Dec 2021 22:50:03 -0800 | Subject | Re: [PATCH v2] perf evsel: Adjust hybrid event and global event mixed group |
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On Tue, Jun 8, 2021 at 9:48 PM Jin Yao <yao.jin@linux.intel.com> wrote: > > A group mixed with hybrid event and global event is allowed. For example, > group leader is 'intel_pt//' and the group member is 'cpu_atom/cycles/'. > > e.g. > perf record --aux-sample -e '{intel_pt//,cpu_atom/cycles/}:u' > > The challenge is their available cpus are not fully matched. For example, > 'intel_pt//' is available on CPU0-CPU23, but 'cpu_atom/cycles/' is > available on CPU16-CPU23. > > When getting the group id for group member, we must be very careful. > Because the cpu for 'intel_pt//' is not equal to the cpu for > 'cpu_atom/cycles/'. Actually the cpu here is the index of evsel->core.cpus, > not the real CPU ID. > > e.g. cpu0 for 'intel_pt//' is CPU0, but cpu0 for 'cpu_atom/cycles/' is CPU16. > > Before: > > # perf record --aux-sample -e '{intel_pt//,cpu_atom/cycles/}:u' -vv uname > ... > ------------------------------------------------------------ > perf_event_attr: > type 10 > size 128 > config 0xe601 > { sample_period, sample_freq } 1 > sample_type IP|TID|TIME|CPU|IDENTIFIER > read_format ID > disabled 1 > inherit 1 > exclude_kernel 1 > exclude_hv 1 > enable_on_exec 1 > sample_id_all 1 > exclude_guest 1 > ------------------------------------------------------------ > sys_perf_event_open: pid 4084 cpu 0 group_fd -1 flags 0x8 = 5 > sys_perf_event_open: pid 4084 cpu 1 group_fd -1 flags 0x8 = 6 > sys_perf_event_open: pid 4084 cpu 2 group_fd -1 flags 0x8 = 7 > sys_perf_event_open: pid 4084 cpu 3 group_fd -1 flags 0x8 = 9 > sys_perf_event_open: pid 4084 cpu 4 group_fd -1 flags 0x8 = 10 > sys_perf_event_open: pid 4084 cpu 5 group_fd -1 flags 0x8 = 11 > sys_perf_event_open: pid 4084 cpu 6 group_fd -1 flags 0x8 = 12 > sys_perf_event_open: pid 4084 cpu 7 group_fd -1 flags 0x8 = 13 > sys_perf_event_open: pid 4084 cpu 8 group_fd -1 flags 0x8 = 14 > sys_perf_event_open: pid 4084 cpu 9 group_fd -1 flags 0x8 = 15 > sys_perf_event_open: pid 4084 cpu 10 group_fd -1 flags 0x8 = 16 > sys_perf_event_open: pid 4084 cpu 11 group_fd -1 flags 0x8 = 17 > sys_perf_event_open: pid 4084 cpu 12 group_fd -1 flags 0x8 = 18 > sys_perf_event_open: pid 4084 cpu 13 group_fd -1 flags 0x8 = 19 > sys_perf_event_open: pid 4084 cpu 14 group_fd -1 flags 0x8 = 20 > sys_perf_event_open: pid 4084 cpu 15 group_fd -1 flags 0x8 = 21 > sys_perf_event_open: pid 4084 cpu 16 group_fd -1 flags 0x8 = 22 > sys_perf_event_open: pid 4084 cpu 17 group_fd -1 flags 0x8 = 23 > sys_perf_event_open: pid 4084 cpu 18 group_fd -1 flags 0x8 = 24 > sys_perf_event_open: pid 4084 cpu 19 group_fd -1 flags 0x8 = 25 > sys_perf_event_open: pid 4084 cpu 20 group_fd -1 flags 0x8 = 26 > sys_perf_event_open: pid 4084 cpu 21 group_fd -1 flags 0x8 = 27 > sys_perf_event_open: pid 4084 cpu 22 group_fd -1 flags 0x8 = 28 > sys_perf_event_open: pid 4084 cpu 23 group_fd -1 flags 0x8 = 29 > ------------------------------------------------------------ > perf_event_attr: > size 128 > config 0x800000000 > { sample_period, sample_freq } 4000 > sample_type IP|TID|TIME|PERIOD|IDENTIFIER|AUX > read_format ID > inherit 1 > exclude_kernel 1 > exclude_hv 1 > freq 1 > sample_id_all 1 > exclude_guest 1 > aux_sample_size 4096 > ------------------------------------------------------------ > sys_perf_event_open: pid 4084 cpu 16 group_fd 5 flags 0x8 > sys_perf_event_open failed, error -22 > > The group_fd 5 is not correct. It should be 22 (the fd of > 'intel_pt' on CPU16). > > After: > > # perf record --aux-sample -e '{intel_pt//,cpu_atom/cycles/}:u' -vv uname > ... > ------------------------------------------------------------ > perf_event_attr: > type 10 > size 128 > config 0xe601 > { sample_period, sample_freq } 1 > sample_type IP|TID|TIME|CPU|IDENTIFIER > read_format ID > disabled 1 > inherit 1 > exclude_kernel 1 > exclude_hv 1 > enable_on_exec 1 > sample_id_all 1 > exclude_guest 1 > ------------------------------------------------------------ > sys_perf_event_open: pid 5162 cpu 0 group_fd -1 flags 0x8 = 5 > sys_perf_event_open: pid 5162 cpu 1 group_fd -1 flags 0x8 = 6 > sys_perf_event_open: pid 5162 cpu 2 group_fd -1 flags 0x8 = 7 > sys_perf_event_open: pid 5162 cpu 3 group_fd -1 flags 0x8 = 9 > sys_perf_event_open: pid 5162 cpu 4 group_fd -1 flags 0x8 = 10 > sys_perf_event_open: pid 5162 cpu 5 group_fd -1 flags 0x8 = 11 > sys_perf_event_open: pid 5162 cpu 6 group_fd -1 flags 0x8 = 12 > sys_perf_event_open: pid 5162 cpu 7 group_fd -1 flags 0x8 = 13 > sys_perf_event_open: pid 5162 cpu 8 group_fd -1 flags 0x8 = 14 > sys_perf_event_open: pid 5162 cpu 9 group_fd -1 flags 0x8 = 15 > sys_perf_event_open: pid 5162 cpu 10 group_fd -1 flags 0x8 = 16 > sys_perf_event_open: pid 5162 cpu 11 group_fd -1 flags 0x8 = 17 > sys_perf_event_open: pid 5162 cpu 12 group_fd -1 flags 0x8 = 18 > sys_perf_event_open: pid 5162 cpu 13 group_fd -1 flags 0x8 = 19 > sys_perf_event_open: pid 5162 cpu 14 group_fd -1 flags 0x8 = 20 > sys_perf_event_open: pid 5162 cpu 15 group_fd -1 flags 0x8 = 21 > sys_perf_event_open: pid 5162 cpu 16 group_fd -1 flags 0x8 = 22 > sys_perf_event_open: pid 5162 cpu 17 group_fd -1 flags 0x8 = 23 > sys_perf_event_open: pid 5162 cpu 18 group_fd -1 flags 0x8 = 24 > sys_perf_event_open: pid 5162 cpu 19 group_fd -1 flags 0x8 = 25 > sys_perf_event_open: pid 5162 cpu 20 group_fd -1 flags 0x8 = 26 > sys_perf_event_open: pid 5162 cpu 21 group_fd -1 flags 0x8 = 27 > sys_perf_event_open: pid 5162 cpu 22 group_fd -1 flags 0x8 = 28 > sys_perf_event_open: pid 5162 cpu 23 group_fd -1 flags 0x8 = 29 > ------------------------------------------------------------ > perf_event_attr: > size 128 > config 0x800000000 > { sample_period, sample_freq } 4000 > sample_type IP|TID|TIME|PERIOD|IDENTIFIER|AUX > read_format ID > inherit 1 > exclude_kernel 1 > exclude_hv 1 > freq 1 > sample_id_all 1 > exclude_guest 1 > aux_sample_size 4096 > ------------------------------------------------------------ > sys_perf_event_open: pid 5162 cpu 16 group_fd 22 flags 0x8 = 30 > sys_perf_event_open: pid 5162 cpu 17 group_fd 23 flags 0x8 = 31 > sys_perf_event_open: pid 5162 cpu 18 group_fd 24 flags 0x8 = 32 > sys_perf_event_open: pid 5162 cpu 19 group_fd 25 flags 0x8 = 33 > sys_perf_event_open: pid 5162 cpu 20 group_fd 26 flags 0x8 = 34 > sys_perf_event_open: pid 5162 cpu 21 group_fd 27 flags 0x8 = 35 > sys_perf_event_open: pid 5162 cpu 22 group_fd 28 flags 0x8 = 36 > sys_perf_event_open: pid 5162 cpu 23 group_fd 29 flags 0x8 = 37 > ------------------------------------------------------------ > ... > > Signed-off-by: Jin Yao <yao.jin@linux.intel.com> > --- > tools/perf/util/evsel.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 4a3cd1b5bb33..f81ac6962aec 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -1581,6 +1581,27 @@ int __evsel__read_on_cpu(struct evsel *evsel, int cpu, int thread, bool scale) > return 0; > } > > +static int evsel__match_other_cpu(struct evsel *evsel, struct evsel *other, > + int cpu) > +{ > + int cpuid; > + > + cpuid = perf_cpu_map__cpu(evsel->core.cpus, cpu);
I came across this as part of: https://lore.kernel.org/lkml/20211208024607.1784932-1-irogers@google.com/ The assumption that evsel's cpu maps are indexable by cpus looks wrong - it wouldn't work for a SkylakeX's: $ cat /sys/devices/uncore_imc_0/cpumask 0,18 The cpu here is a real CPU and not a cpu map index, so I'm not sure what the cpu map translation is trying to do - if this is a full cpu map then cpuid will equal cpu. Perhaps the code should be: BUG_ON(!perf_cpu_map__has(evsel->core.cpus, cpu)); return perf_cpu_map__idx(other->core.cpus, cpu);
Thanks, Ian
> + return perf_cpu_map__idx(other->core.cpus, cpuid); > +} > + > +static int evsel__hybrid_group_cpu(struct evsel *evsel, int cpu) > +{ > + struct evsel *leader = evsel->leader; > + > + if ((evsel__is_hybrid(evsel) && !evsel__is_hybrid(leader)) || > + (!evsel__is_hybrid(evsel) && evsel__is_hybrid(leader))) { > + return evsel__match_other_cpu(evsel, leader, cpu); > + } > + > + return cpu; > +} > + > static int get_group_fd(struct evsel *evsel, int cpu, int thread) > { > struct evsel *leader = evsel->leader; > @@ -1595,6 +1616,10 @@ static int get_group_fd(struct evsel *evsel, int cpu, int thread) > */ > BUG_ON(!leader->core.fd); > > + cpu = evsel__hybrid_group_cpu(evsel, cpu); > + if (cpu == -1) > + return -1; > + > fd = FD(leader, cpu, thread); > BUG_ON(fd == -1); > > -- > 2.17.1 >
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