[PATCH 06/11] perf evsel: Introduce per cpu and per thread open helpers

Arnaldo Carvalho de Melo
2011-01-04T03:49:06Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

Abstracting away the loops needed to create the various event fd handlers.

The users have to pass a confiruged perf->evsel.attr field, which is already
usable after perf_evsel__new (constructor) time, using defaults.

Comes out of the ad-hoc routines in builtin-stat, that now uses it.

Fixed a small silly bug where we were die()ing before killing our
children, dysfunctional family this one 8-)

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-stat.c | 84 ++++++++++++++-------------------------------
tools/perf/util/evsel.c | 52 ++++++++++++++++++++++++++++
tools/perf/util/evsel.h | 5 +++
3 files changed, 83 insertions(+), 58 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a8b00b4..065e79e 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -53,8 +53,6 @@
#include <math.h>
#include <locale.h>

-#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
-
#define DEFAULT_SEPARATOR " "

static struct perf_event_attr default_attrs[] = {
@@ -160,56 +158,24 @@ struct stats runtime_cycles_stats[MAX_NR_CPUS];
struct stats runtime_branches_stats[MAX_NR_CPUS];
struct stats walltime_nsecs_stats;

-#define ERR_PERF_OPEN \
-"counter %d, sys_perf_event_open() syscall returned with %d (%s). /bin/dmesg may provide additional information."
-
-static int create_perf_stat_counter(struct perf_evsel *evsel, bool *perm_err)
+static int create_perf_stat_counter(struct perf_evsel *evsel)
{
struct perf_event_attr *attr = &evsel->attr;
- int thread;
- int ncreated = 0;

if (scale)
attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
PERF_FORMAT_TOTAL_TIME_RUNNING;

- if (system_wide) {
- int cpu;
-
- for (cpu = 0; cpu < nr_cpus; cpu++) {
- FD(evsel, cpu, 0) = sys_perf_event_open(attr,
- -1, cpumap[cpu], -1, 0);
- if (FD(evsel, cpu, 0) < 0) {
- if (errno == EPERM || errno == EACCES)
- *perm_err = true;
- error(ERR_PERF_OPEN, evsel->idx,
- FD(evsel, cpu, 0), strerror(errno));
- } else {
- ++ncreated;
- }
- }
- } else {
- attr->inherit = !no_inherit;
- if (target_pid == -1 && target_tid == -1) {
- attr->disabled = 1;
- attr->enable_on_exec = 1;
- }
- for (thread = 0; thread < thread_num; thread++) {
- FD(evsel, 0, thread) = sys_perf_event_open(attr,
- all_tids[thread], -1, -1, 0);
- if (FD(evsel, 0, thread) < 0) {
- if (errno == EPERM || errno == EACCES)
- *perm_err = true;
- error(ERR_PERF_OPEN, evsel->idx,
- FD(evsel, 0, thread),
- strerror(errno));
- } else {
- ++ncreated;
- }
- }
+ if (system_wide)
+ return perf_evsel__open_per_cpu(evsel, nr_cpus, cpumap);
+
+ attr->inherit = !no_inherit;
+ if (target_pid == -1 && target_tid == -1) {
+ attr->disabled = 1;
+ attr->enable_on_exec = 1;
}

- return ncreated;
+ return perf_evsel__open_per_thread(evsel, thread_num, all_tids);
}

/*
@@ -289,9 +255,7 @@ static int run_perf_stat(int argc __used, const char **argv)
unsigned long long t0, t1;
struct perf_evsel *counter;
int status = 0;
- int ncreated = 0;
int child_ready_pipe[2], go_pipe[2];
- bool perm_err = false;
const bool forks = (argc > 0);
char buf;

@@ -349,19 +313,23 @@ static int run_perf_stat(int argc __used, const char **argv)
close(child_ready_pipe[0]);
}

- list_for_each_entry(counter, &evsel_list, node)
- ncreated += create_perf_stat_counter(counter, &perm_err);
-
- if (ncreated < nr_counters) {
- if (perm_err)
- error("You may not have permission to collect %sstats.\n"
- "\t Consider tweaking"
- " /proc/sys/kernel/perf_event_paranoid or running as root.",
- system_wide ? "system-wide " : "");
- die("Not all events could be opened.\n");
- if (child_pid != -1)
- kill(child_pid, SIGTERM);
- return -1;
+ list_for_each_entry(counter, &evsel_list, node) {
+ if (create_perf_stat_counter(counter) < 0) {
+ if (errno == -EPERM || errno == -EACCES) {
+ error("You may not have permission to collect %sstats.\n"
+ "\t Consider tweaking"
+ " /proc/sys/kernel/perf_event_paranoid or running as root.",
+ system_wide ? "system-wide " : "");
+ } else {
+ error("open_counter returned with %d (%s). "
+ "/bin/dmesg may provide additional information.\n",
+ errno, strerror(errno));
+ }
+ if (child_pid != -1)
+ kill(child_pid, SIGTERM);
+ die("Not all events could be opened.\n");
+ return -1;
+ }
}

/*
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3f5de51..e62cc5e 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1,4 +1,5 @@
#include "evsel.h"
+#include "../perf.h"
#include "util.h"

#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
@@ -121,3 +122,54 @@ int __perf_evsel__read(struct perf_evsel *evsel,

return 0;
}
+
+int perf_evsel__open_per_cpu(struct perf_evsel *evsel, int ncpus, int *cpu_map)
+{
+ int cpu;
+
+ for (cpu = 0; cpu < ncpus; cpu++) {
+ FD(evsel, cpu, 0) = sys_perf_event_open(&evsel->attr, -1,
+ cpu_map[cpu], -1, 0);
+ if (FD(evsel, cpu, 0) < 0)
+ goto out_close;
+ }
+
+ return 0;
+
+out_close:
+ while (--cpu >= 0) {
+ close(FD(evsel, cpu, 0));
+ FD(evsel, cpu, 0) = -1;
+ }
+ return -1;
+}
+
+int perf_evsel__open_per_thread(struct perf_evsel *evsel, int nthreads, int *thread_map)
+{
+ int thread;
+
+ for (thread = 0; thread < nthreads; thread++) {
+ FD(evsel, 0, thread) = sys_perf_event_open(&evsel->attr,
+ thread_map[thread], -1, -1, 0);
+ if (FD(evsel, 0, thread) < 0)
+ goto out_close;
+ }
+
+ return 0;
+
+out_close:
+ while (--thread >= 0) {
+ close(FD(evsel, 0, thread));
+ FD(evsel, 0, thread) = -1;
+ }
+ return -1;
+}
+
+int perf_evsel__open(struct perf_evsel *evsel, int ncpus, int nthreads,
+ int *cpu_map, int *thread_map)
+{
+ if (nthreads < 0)
+ return perf_evsel__open_per_cpu(evsel, ncpus, cpu_map);
+
+ return perf_evsel__open_per_thread(evsel, nthreads, thread_map);
+}
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 8b48ef1..a62fb55 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -42,6 +42,11 @@ int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus);
void perf_evsel__free_fd(struct perf_evsel *evsel);
void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);

+int perf_evsel__open_per_cpu(struct perf_evsel *evsel, int ncpus, int *cpu_map);
+int perf_evsel__open_per_thread(struct perf_evsel *evsel, int nthreads, int *thread_map);
+int perf_evsel__open(struct perf_evsel *evsel, int ncpus, int nthreads,
+ int *cpu_map, int *thread_map);
+
#define perf_evsel__match(evsel, t, c) \
(evsel->attr.type == PERF_TYPE_##t && \
evsel->attr.config == PERF_COUNT_##c)
--
1.6.2.5