[tip:perf/core] perf evlist: Add 'system_wide' option

From: tip-bot for Adrian Hunter
Date: Thu Aug 14 2014 - 04:51:31 EST

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Commit-ID: bf8e8f4b832972c76d64ab2e2837a48397144887
Gitweb: http://git.kernel.org/tip/bf8e8f4b832972c76d64ab2e2837a48397144887
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Thu, 31 Jul 2014 09:00:51 +0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 13 Aug 2014 19:21:18 -0300

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@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1406786474-9306-9-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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 3b366c0..c74d8ec 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 0c8919d..66de9a7 100644
--- 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
--- 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;
--
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Next message: tip-bot for Adrian Hunter: "[tip:perf/core] perf evlist: Add perf_evlist__set_tracking_event( )"
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