#include <subcmd/parse-options.h>
#include <perf/cpumap.h>
#include "cloexec.h"
+#include "util/perf_api_probe.h"
#include "record.h"
#include "../perf-sys.h"
-typedef void (*setup_probe_fn_t)(struct evsel *evsel);
-
-static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
+/*
+ * evsel__config_leader_sampling() uses special rules for leader sampling.
+ * However, if the leader is an AUX area event, then assume the event to sample
+ * is the next event.
+ */
+static struct evsel *perf_evsel__read_sampler(struct evsel *evsel,
+ struct evlist *evlist)
{
- struct evlist *evlist;
- struct evsel *evsel;
- unsigned long flags = perf_event_open_cloexec_flag();
- int err = -EAGAIN, fd;
- static pid_t pid = -1;
-
- evlist = evlist__new();
- if (!evlist)
- return -ENOMEM;
-
- if (parse_events(evlist, str, NULL))
- goto out_delete;
-
- evsel = evlist__first(evlist);
+ struct evsel *leader = evsel->leader;
- while (1) {
- fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1, flags);
- if (fd < 0) {
- if (pid == -1 && errno == EACCES) {
- pid = 0;
- continue;
- }
- goto out_delete;
+ if (evsel__is_aux_event(leader)) {
+ evlist__for_each_entry(evlist, evsel) {
+ if (evsel->leader == leader && evsel != evsel->leader)
+ return evsel;
}
- break;
- }
- close(fd);
-
- fn(evsel);
-
- fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1, flags);
- if (fd < 0) {
- if (errno == EINVAL)
- err = -EINVAL;
- goto out_delete;
}
- close(fd);
- err = 0;
-
-out_delete:
- evlist__delete(evlist);
- return err;
-}
-
-static bool perf_probe_api(setup_probe_fn_t fn)
-{
- const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
- struct perf_cpu_map *cpus;
- int cpu, ret, i = 0;
-
- cpus = perf_cpu_map__new(NULL);
- if (!cpus)
- return false;
- cpu = cpus->map[0];
- perf_cpu_map__put(cpus);
-
- do {
- ret = perf_do_probe_api(fn, cpu, try[i++]);
- if (!ret)
- return true;
- } while (ret == -EAGAIN && try[i]);
- return false;
+ return leader;
}
-static void perf_probe_sample_identifier(struct evsel *evsel)
+static void evsel__config_leader_sampling(struct evsel *evsel, struct evlist *evlist)
{
- evsel->core.attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
-}
-
-static void perf_probe_comm_exec(struct evsel *evsel)
-{
- evsel->core.attr.comm_exec = 1;
-}
-
-static void perf_probe_context_switch(struct evsel *evsel)
-{
- evsel->core.attr.context_switch = 1;
-}
-
-bool perf_can_sample_identifier(void)
-{
- return perf_probe_api(perf_probe_sample_identifier);
-}
+ struct perf_event_attr *attr = &evsel->core.attr;
+ struct evsel *leader = evsel->leader;
+ struct evsel *read_sampler;
-static bool perf_can_comm_exec(void)
-{
- return perf_probe_api(perf_probe_comm_exec);
-}
+ if (!leader->sample_read)
+ return;
-bool perf_can_record_switch_events(void)
-{
- return perf_probe_api(perf_probe_context_switch);
-}
+ read_sampler = perf_evsel__read_sampler(evsel, evlist);
-bool perf_can_record_cpu_wide(void)
-{
- struct perf_event_attr attr = {
- .type = PERF_TYPE_SOFTWARE,
- .config = PERF_COUNT_SW_CPU_CLOCK,
- .exclude_kernel = 1,
- };
- struct perf_cpu_map *cpus;
- int cpu, fd;
-
- cpus = perf_cpu_map__new(NULL);
- if (!cpus)
- return false;
- cpu = cpus->map[0];
- perf_cpu_map__put(cpus);
+ if (evsel == read_sampler)
+ return;
- fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
- if (fd < 0)
- return false;
- close(fd);
-
- return true;
-}
-
-/*
- * Architectures are expected to know if AUX area sampling is supported by the
- * hardware. Here we check for kernel support.
- */
-bool perf_can_aux_sample(void)
-{
- struct perf_event_attr attr = {
- .size = sizeof(struct perf_event_attr),
- .exclude_kernel = 1,
- /*
- * Non-zero value causes the kernel to calculate the effective
- * attribute size up to that byte.
- */
- .aux_sample_size = 1,
- };
- int fd;
-
- fd = sys_perf_event_open(&attr, -1, 0, -1, 0);
/*
- * If the kernel attribute is big enough to contain aux_sample_size
- * then we assume that it is supported. We are relying on the kernel to
- * validate the attribute size before anything else that could be wrong.
+ * Disable sampling for all group members other than the leader in
+ * case the leader 'leads' the sampling, except when the leader is an
+ * AUX area event, in which case the 2nd event in the group is the one
+ * that 'leads' the sampling.
*/
- if (fd < 0 && errno == E2BIG)
- return false;
- if (fd >= 0)
- close(fd);
+ attr->freq = 0;
+ attr->sample_freq = 0;
+ attr->sample_period = 0;
+ attr->write_backward = 0;
- return true;
+ /*
+ * We don't get a sample for slave events, we make them when delivering
+ * the group leader sample. Set the slave event to follow the master
+ * sample_type to ease up reporting.
+ * An AUX area event also has sample_type requirements, so also include
+ * the sample type bits from the leader's sample_type to cover that
+ * case.
+ */
+ attr->sample_type = read_sampler->core.attr.sample_type |
+ leader->core.attr.sample_type;
}
void perf_evlist__config(struct evlist *evlist, struct record_opts *opts,
use_comm_exec = perf_can_comm_exec();
evlist__for_each_entry(evlist, evsel) {
- perf_evsel__config(evsel, opts, callchain);
+ evsel__config(evsel, opts, callchain);
if (evsel->tracking && use_comm_exec)
evsel->core.attr.comm_exec = 1;
}
+ /* Configure leader sampling here now that the sample type is known */
+ evlist__for_each_entry(evlist, evsel)
+ evsel__config_leader_sampling(evsel, evlist);
+
if (opts->full_auxtrace) {
/*
* Need to be able to synthesize and parse selected events with
projects / linux-2.6-microblaze.git / blobdiff