linux/tools/perf/util/evlist-hybrid.c
Zhengjun Xing 8a3d2ee0de perf evlist: Fix failed to use cpu list for uncore events
The 'perf record' and 'perf stat' commands have supported the option
'-C/--cpus' to count or collect only on the list of CPUs provided.

Commit 1d3351e631 ("perf tools: Enable on a list of CPUs for
hybrid") add it to be supported for hybrid. For hybrid support, it
checks the cpu list are available on hybrid PMU. But when we test only
uncore events(or events not in cpu_core and cpu_atom), there is a bug:

Before:

 # perf stat -C0  -e uncore_clock/clockticks/ sleep 1
   failed to use cpu list 0

In this case, for uncore event, its pmu_name is not cpu_core or
cpu_atom, so in evlist__fix_hybrid_cpus, perf_pmu__find_hybrid_pmu
should return NULL,both events_nr and unmatched_count should be 0 ,then
the cpu list check function evlist__fix_hybrid_cpus return -1 and the
error "failed to use cpu list 0" will happen. Bypass "events_nr=0" case
then the issue is fixed.

After:

 # perf stat -C0  -e uncore_clock/clockticks/ sleep 1

 Performance counter stats for 'CPU(s) 0':

       195,476,873      uncore_clock/clockticks/

       1.004518677 seconds time elapsed

When testing with at least one core event and uncore events, it has no
issue.

 # perf stat -C0  -e cpu_core/cpu-cycles/,uncore_clock/clockticks/ sleep 1

 Performance counter stats for 'CPU(s) 0':

         5,993,774      cpu_core/cpu-cycles/
       301,025,912      uncore_clock/clockticks/

       1.003964934 seconds time elapsed

Fixes: 1d3351e631 ("perf tools: Enable on a list of CPUs for hybrid")
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: alexander.shishkin@intel.com
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20220218093127.1844241-1-zhengjun.xing@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-02-18 09:59:26 -03:00

163 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <errno.h>
#include <inttypes.h>
#include "cpumap.h"
#include "evlist.h"
#include "evsel.h"
#include "../perf.h"
#include "util/pmu-hybrid.h"
#include "util/evlist-hybrid.h"
#include "debug.h"
#include <unistd.h>
#include <stdlib.h>
#include <linux/err.h>
#include <linux/string.h>
#include <perf/evlist.h>
#include <perf/evsel.h>
#include <perf/cpumap.h>
int evlist__add_default_hybrid(struct evlist *evlist, bool precise)
{
struct evsel *evsel;
struct perf_pmu *pmu;
__u64 config;
struct perf_cpu_map *cpus;
perf_pmu__for_each_hybrid_pmu(pmu) {
config = PERF_COUNT_HW_CPU_CYCLES |
((__u64)pmu->type << PERF_PMU_TYPE_SHIFT);
evsel = evsel__new_cycles(precise, PERF_TYPE_HARDWARE,
config);
if (!evsel)
return -ENOMEM;
cpus = perf_cpu_map__get(pmu->cpus);
evsel->core.cpus = cpus;
evsel->core.own_cpus = perf_cpu_map__get(cpus);
evsel->pmu_name = strdup(pmu->name);
evlist__add(evlist, evsel);
}
return 0;
}
static bool group_hybrid_conflict(struct evsel *leader)
{
struct evsel *pos, *prev = NULL;
for_each_group_evsel(pos, leader) {
if (!evsel__is_hybrid(pos))
continue;
if (prev && strcmp(prev->pmu_name, pos->pmu_name))
return true;
prev = pos;
}
return false;
}
void evlist__warn_hybrid_group(struct evlist *evlist)
{
struct evsel *evsel;
evlist__for_each_entry(evlist, evsel) {
if (evsel__is_group_leader(evsel) &&
evsel->core.nr_members > 1 &&
group_hybrid_conflict(evsel)) {
pr_warning("WARNING: events in group from "
"different hybrid PMUs!\n");
return;
}
}
}
bool evlist__has_hybrid(struct evlist *evlist)
{
struct evsel *evsel;
evlist__for_each_entry(evlist, evsel) {
if (evsel->pmu_name &&
perf_pmu__is_hybrid(evsel->pmu_name)) {
return true;
}
}
return false;
}
int evlist__fix_hybrid_cpus(struct evlist *evlist, const char *cpu_list)
{
struct perf_cpu_map *cpus;
struct evsel *evsel, *tmp;
struct perf_pmu *pmu;
int ret, unmatched_count = 0, events_nr = 0;
if (!perf_pmu__has_hybrid() || !cpu_list)
return 0;
cpus = perf_cpu_map__new(cpu_list);
if (!cpus)
return -1;
/*
* The evsels are created with hybrid pmu's cpus. But now we
* need to check and adjust the cpus of evsel by cpu_list because
* cpu_list may cause conflicts with cpus of evsel. For example,
* cpus of evsel is cpu0-7, but the cpu_list is cpu6-8, we need
* to adjust the cpus of evsel to cpu6-7. And then propatate maps
* in evlist__create_maps().
*/
evlist__for_each_entry_safe(evlist, tmp, evsel) {
struct perf_cpu_map *matched_cpus, *unmatched_cpus;
char buf1[128], buf2[128];
pmu = perf_pmu__find_hybrid_pmu(evsel->pmu_name);
if (!pmu)
continue;
ret = perf_pmu__cpus_match(pmu, cpus, &matched_cpus,
&unmatched_cpus);
if (ret)
goto out;
events_nr++;
if (perf_cpu_map__nr(matched_cpus) > 0 &&
(perf_cpu_map__nr(unmatched_cpus) > 0 ||
perf_cpu_map__nr(matched_cpus) < perf_cpu_map__nr(cpus) ||
perf_cpu_map__nr(matched_cpus) < perf_cpu_map__nr(pmu->cpus))) {
perf_cpu_map__put(evsel->core.cpus);
perf_cpu_map__put(evsel->core.own_cpus);
evsel->core.cpus = perf_cpu_map__get(matched_cpus);
evsel->core.own_cpus = perf_cpu_map__get(matched_cpus);
if (perf_cpu_map__nr(unmatched_cpus) > 0) {
cpu_map__snprint(matched_cpus, buf1, sizeof(buf1));
pr_warning("WARNING: use %s in '%s' for '%s', skip other cpus in list.\n",
buf1, pmu->name, evsel->name);
}
}
if (perf_cpu_map__nr(matched_cpus) == 0) {
evlist__remove(evlist, evsel);
evsel__delete(evsel);
cpu_map__snprint(cpus, buf1, sizeof(buf1));
cpu_map__snprint(pmu->cpus, buf2, sizeof(buf2));
pr_warning("WARNING: %s isn't a '%s', please use a CPU list in the '%s' range (%s)\n",
buf1, pmu->name, pmu->name, buf2);
unmatched_count++;
}
perf_cpu_map__put(matched_cpus);
perf_cpu_map__put(unmatched_cpus);
}
if (events_nr)
ret = (unmatched_count == events_nr) ? -1 : 0;
out:
perf_cpu_map__put(cpus);
return ret;
}