perf evsel: Introduce per cpu and per thread open helpers

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>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3f5de519623..e62cc5e050a 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);
+}