[PATCH 18/52] perf evlist: Add 'system_wide' option

Adrian Hunter
2014-07-22T13:31:03Z

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>
---
tools/perf/util/evlist.c | 45 +++++++++++++++++++++++++++++++++++++--------
tools/perf/util/evsel.c | 31 ++++++++++++++++++++++++++-----
tools/perf/util/evsel.h | 1 +
3 files changed, 64 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 282e83e..c295b7b 100644
--- 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 21a373e..7baa06f 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -692,6 +692,10 @@ 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) {
@@ -710,6 +714,9 @@ 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),
@@ -740,6 +747,9 @@ 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;
@@ -784,6 +794,9 @@ 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));
@@ -872,6 +885,9 @@ 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++) {
@@ -994,13 +1010,18 @@ 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) {
@@ -1024,10 +1045,10 @@ 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);
@@ -1100,7 +1121,7 @@ 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
--- 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;
--
1.8.3.2