perf evlist: Add 'system_wide' option

Add an option to cause a selected event to be opened always without a
pid when configured by perf_evsel__config().

This is needed when using the sched_switch tracepoint to follow object
code execution.

sched_switch occurs before the task switch and so it cannot record it in
a context limited to that task.  Note that also means that sched_switch
is useless when capturing data per-thread, as is the 'context-switches'
software event for the same reason.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1406786474-9306-9-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 3b366c0..c74d8ec 100644 (file)
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -265,17 +265,27 @@ int perf_evlist__add_newtp(struct perf_evlist *evlist,
        return 0;
 }
 
+static int perf_evlist__nr_threads(struct perf_evlist *evlist,
+                                  struct perf_evsel *evsel)
+{
+       if (evsel->system_wide)
+               return 1;
+       else
+               return thread_map__nr(evlist->threads);
+}
+
 void perf_evlist__disable(struct perf_evlist *evlist)
 {
        int cpu, thread;
        struct perf_evsel *pos;
        int nr_cpus = cpu_map__nr(evlist->cpus);
-       int nr_threads = thread_map__nr(evlist->threads);
+       int nr_threads;
 
        for (cpu = 0; cpu < nr_cpus; cpu++) {
                evlist__for_each(evlist, pos) {
                        if (!perf_evsel__is_group_leader(pos) || !pos->fd)
                                continue;
+                       nr_threads = perf_evlist__nr_threads(evlist, pos);
                        for (thread = 0; thread < nr_threads; thread++)
                                ioctl(FD(pos, cpu, thread),
                                      PERF_EVENT_IOC_DISABLE, 0);
@@ -288,12 +298,13 @@ void perf_evlist__enable(struct perf_evlist *evlist)
        int cpu, thread;
        struct perf_evsel *pos;
        int nr_cpus = cpu_map__nr(evlist->cpus);
-       int nr_threads = thread_map__nr(evlist->threads);
+       int nr_threads;
 
        for (cpu = 0; cpu < nr_cpus; cpu++) {
                evlist__for_each(evlist, pos) {
                        if (!perf_evsel__is_group_leader(pos) || !pos->fd)
                                continue;
+                       nr_threads = perf_evlist__nr_threads(evlist, pos);
                        for (thread = 0; thread < nr_threads; thread++)
                                ioctl(FD(pos, cpu, thread),
                                      PERF_EVENT_IOC_ENABLE, 0);
@@ -305,12 +316,14 @@ int perf_evlist__disable_event(struct perf_evlist *evlist,
                               struct perf_evsel *evsel)
 {
        int cpu, thread, err;
+       int nr_cpus = cpu_map__nr(evlist->cpus);
+       int nr_threads = perf_evlist__nr_threads(evlist, evsel);
 
        if (!evsel->fd)
                return 0;
 
-       for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
-               for (thread = 0; thread < evlist->threads->nr; thread++) {
+       for (cpu = 0; cpu < nr_cpus; cpu++) {
+               for (thread = 0; thread < nr_threads; thread++) {
                        err = ioctl(FD(evsel, cpu, thread),
                                    PERF_EVENT_IOC_DISABLE, 0);
                        if (err)
@@ -324,12 +337,14 @@ int perf_evlist__enable_event(struct perf_evlist *evlist,
                              struct perf_evsel *evsel)
 {
        int cpu, thread, err;
+       int nr_cpus = cpu_map__nr(evlist->cpus);
+       int nr_threads = perf_evlist__nr_threads(evlist, evsel);
 
        if (!evsel->fd)
                return -EINVAL;
 
-       for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
-               for (thread = 0; thread < evlist->threads->nr; thread++) {
+       for (cpu = 0; cpu < nr_cpus; cpu++) {
+               for (thread = 0; thread < nr_threads; thread++) {
                        err = ioctl(FD(evsel, cpu, thread),
                                    PERF_EVENT_IOC_ENABLE, 0);
                        if (err)
@@ -343,7 +358,16 @@ static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 {
        int nr_cpus = cpu_map__nr(evlist->cpus);
        int nr_threads = thread_map__nr(evlist->threads);
-       int nfds = nr_cpus * nr_threads * evlist->nr_entries;
+       int nfds = 0;
+       struct perf_evsel *evsel;
+
+       list_for_each_entry(evsel, &evlist->entries, node) {
+               if (evsel->system_wide)
+                       nfds += nr_cpus;
+               else
+                       nfds += nr_cpus * nr_threads;
+       }
+
        evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
        return evlist->pollfd != NULL ? 0 : -ENOMEM;
 }
@@ -636,7 +660,12 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx,
        struct perf_evsel *evsel;
 
        evlist__for_each(evlist, evsel) {
-               int fd = FD(evsel, cpu, thread);
+               int fd;
+
+               if (evsel->system_wide && thread)
+                       continue;
+
+               fd = FD(evsel, cpu, thread);
 
                if (*output == -1) {
                        *output = fd;

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0c8919d..66de9a7 100644 (file)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -695,6 +695,10 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
 {
        int cpu, thread;
+
+       if (evsel->system_wide)
+               nthreads = 1;
+
        evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
 
        if (evsel->fd) {
@@ -713,6 +717,9 @@ static int perf_evsel__run_ioctl(struct perf_evsel *evsel, int ncpus, int nthrea
 {
        int cpu, thread;
 
+       if (evsel->system_wide)
+               nthreads = 1;
+
        for (cpu = 0; cpu < ncpus; cpu++) {
                for (thread = 0; thread < nthreads; thread++) {
                        int fd = FD(evsel, cpu, thread),
@@ -743,6 +750,9 @@ int perf_evsel__enable(struct perf_evsel *evsel, int ncpus, int nthreads)
 
 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
 {
+       if (evsel->system_wide)
+               nthreads = 1;
+
        evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
        if (evsel->sample_id == NULL)
                return -ENOMEM;
@@ -787,6 +797,9 @@ void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
 {
        int cpu, thread;
 
+       if (evsel->system_wide)
+               nthreads = 1;
+
        for (cpu = 0; cpu < ncpus; cpu++)
                for (thread = 0; thread < nthreads; ++thread) {
                        close(FD(evsel, cpu, thread));
@@ -875,6 +888,9 @@ int __perf_evsel__read(struct perf_evsel *evsel,
        int cpu, thread;
        struct perf_counts_values *aggr = &evsel->counts->aggr, count;
 
+       if (evsel->system_wide)
+               nthreads = 1;
+
        aggr->val = aggr->ena = aggr->run = 0;
 
        for (cpu = 0; cpu < ncpus; cpu++) {
@@ -997,13 +1013,18 @@ static size_t perf_event_attr__fprintf(struct perf_event_attr *attr, FILE *fp)
 static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
                              struct thread_map *threads)
 {
-       int cpu, thread;
+       int cpu, thread, nthreads;
        unsigned long flags = PERF_FLAG_FD_CLOEXEC;
        int pid = -1, err;
        enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE;
 
+       if (evsel->system_wide)
+               nthreads = 1;
+       else
+               nthreads = threads->nr;
+
        if (evsel->fd == NULL &&
-           perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0)
+           perf_evsel__alloc_fd(evsel, cpus->nr, nthreads) < 0)
                return -ENOMEM;
 
        if (evsel->cgrp) {
@@ -1027,10 +1048,10 @@ retry_sample_id:
 
        for (cpu = 0; cpu < cpus->nr; cpu++) {
 
-               for (thread = 0; thread < threads->nr; thread++) {
+               for (thread = 0; thread < nthreads; thread++) {
                        int group_fd;
 
-                       if (!evsel->cgrp)
+                       if (!evsel->cgrp && !evsel->system_wide)
                                pid = threads->map[thread];
 
                        group_fd = get_group_fd(evsel, cpu, thread);
@@ -1103,7 +1124,7 @@ out_close:
                        close(FD(evsel, cpu, thread));
                        FD(evsel, cpu, thread) = -1;
                }
-               thread = threads->nr;
+               thread = nthreads;
        } while (--cpu >= 0);
        return err;
 }

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index d7f93ce..dbb2a0d 100644 (file)
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -85,6 +85,7 @@ struct perf_evsel {
        bool                    needs_swap;
        bool                    no_aux_samples;
        bool                    immediate;
+       bool                    system_wide;
        /* parse modifier helper */
        int                     exclude_GH;
        int                     nr_members;