Commit b91917c0 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf bpf_counter: Fix handling of cpumap fixing hybrid 



Don't open evsels on all CPUs, open them just on the CPUs they
support. This avoids opening say an e-core event on a p-core and
getting a failure - achieve this by getting rid of the "all_cpu_map".

In install_pe functions don't use the cpu_map_idx as a CPU number,
translate the cpu_map_idx, which is a dense index into the cpu_map
skipping holes at the beginning, to a proper CPU number.

Before:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1

 Performance counter stats for 'system wide':

   <not supported>      cpu_atom/cycles/
       566,270,672      cpu_core/cycles/
   <not supported>      cpu_atom/instructions/
       572,792,836      cpu_core/instructions/           #    1.01  insn per cycle

       1.001595384 seconds time elapsed
```

After:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1

 Performance counter stats for 'system wide':

       443,299,201      cpu_atom/cycles/
     1,233,919,737      cpu_core/cycles/
       213,634,112      cpu_atom/instructions/           #    0.48  insn per cycle
     2,758,965,527      cpu_core/instructions/           #    2.24  insn per cycle

       1.001699485 seconds time elapsed
```

Fixes: 7fac83aa ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: bpf@vger.kernel.org
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 8c519a82

tools/perf/util/bpf_counter.c

+10 −16
Original line number Diff line number Diff line
@@ -336,6 +336,7 @@ static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu_map_idx 
{

	struct bpf_prog_profiler_bpf *skel;

	struct bpf_counter *counter;

	int cpu = perf_cpu_map__cpu(evsel->core.cpus, cpu_map_idx).cpu;

	int ret;



	list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
@@ -343,7 +344,7 @@ static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu_map_idx 
		assert(skel != NULL);



		ret = bpf_map_update_elem(bpf_map__fd(skel->maps.events),

					  &cpu_map_idx, &fd, BPF_ANY);

					  &cpu, &fd, BPF_ANY);

		if (ret)

			return ret;

	}
@@ -451,7 +452,6 @@ static int bperf_check_target(struct evsel *evsel, 
	return 0;

}



static	struct perf_cpu_map *all_cpu_map;

static __u32 filter_entry_cnt;



static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd,
@@ -495,7 +495,7 @@ static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd, 
	 * following evsel__open_per_cpu call

	 */

	evsel->leader_skel = skel;

	evsel__open_per_cpu(evsel, all_cpu_map, -1);

	evsel__open(evsel, evsel->core.cpus, evsel->core.threads);



out:

	bperf_leader_bpf__destroy(skel);
@@ -533,12 +533,6 @@ static int bperf__load(struct evsel *evsel, struct target *target) 
	if (bperf_check_target(evsel, target, &filter_type, &filter_entry_cnt))

		return -1;



	if (!all_cpu_map) {

		all_cpu_map = perf_cpu_map__new_online_cpus();

		if (!all_cpu_map)

			return -1;

	}



	evsel->bperf_leader_prog_fd = -1;

	evsel->bperf_leader_link_fd = -1;
@@ -656,9 +650,10 @@ static int bperf__load(struct evsel *evsel, struct target *target) 
static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)

{

	struct bperf_leader_bpf *skel = evsel->leader_skel;

	int cpu = perf_cpu_map__cpu(evsel->core.cpus, cpu_map_idx).cpu;



	return bpf_map_update_elem(bpf_map__fd(skel->maps.events),

				   &cpu_map_idx, &fd, BPF_ANY);

				   &cpu, &fd, BPF_ANY);

}



/*
@@ -667,13 +662,12 @@ static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd) 
 */

static int bperf_sync_counters(struct evsel *evsel)

{

	int num_cpu, i, cpu;

	struct perf_cpu cpu;

	int idx;



	perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus)

		bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu.cpu);



	num_cpu = perf_cpu_map__nr(all_cpu_map);

	for (i = 0; i < num_cpu; i++) {

		cpu = perf_cpu_map__cpu(all_cpu_map, i).cpu;

		bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu);

	}

	return 0;

}

tools/perf/util/bpf_counter_cgroup.c

+2 −1
Original line number Diff line number Diff line
@@ -186,7 +186,8 @@ static int bperf_cgrp__load(struct evsel *evsel, 
}



static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused,

				  int cpu __maybe_unused, int fd __maybe_unused)

				  int cpu_map_idx __maybe_unused,

				  int fd __maybe_unused)

{

	/* nothing to do */

	return 0;