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perf evlist: Add 'system_wide' option
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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>
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Adrian Hunter authored and Arnaldo Carvalho de Melo committed Aug 13, 2014
1 parent f247fb8 commit bf8e8f4
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Showing 3 changed files with 64 additions and 13 deletions.
45 changes: 37 additions & 8 deletions tools/perf/util/evlist.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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);
Expand All @@ -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)
Expand All @@ -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)
Expand All @@ -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;
}
Expand Down Expand Up @@ -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;
Expand Down
31 changes: 26 additions & 5 deletions tools/perf/util/evsel.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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) {
Expand All @@ -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),
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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));
Expand Down Expand Up @@ -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++) {
Expand Down Expand Up @@ -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) {
Expand All @@ -1027,10 +1048,10 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,

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);
Expand Down Expand Up @@ -1103,7 +1124,7 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
close(FD(evsel, cpu, thread));
FD(evsel, cpu, thread) = -1;
}
thread = threads->nr;
thread = nthreads;
} while (--cpu >= 0);
return err;
}
Expand Down
1 change: 1 addition & 0 deletions tools/perf/util/evsel.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down

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