perf evlist: Introduce poll method for common code idiom

Since we have access two evlist members in all these poll calls, provide
a helper.

This will also help to make the patch introducing the pollfd class more
clear, as the evlist specific uses will be hiden away
perf_evlist__poll().

Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-jr9d4aop4lvy9453qahbcgp0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index a1b0403..a8c2e9d 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -459,7 +459,7 @@
 		if (hits == rec->samples) {
 			if (done)
 				break;
-			err = poll(rec->evlist->pollfd, rec->evlist->nr_fds, -1);
+			err = perf_evlist__poll(rec->evlist, -1);
 			/*
 			 * Propagate error, only if there's any. Ignore positive
 			 * number of returned events and interrupt error.
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index e13864b..832fb52 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -964,7 +964,7 @@
                 perf_evlist__enable(top->evlist);
 
 	/* Wait for a minimal set of events before starting the snapshot */
-	poll(top->evlist->pollfd, top->evlist->nr_fds, 100);
+	perf_evlist__poll(top->evlist, 100);
 
 	perf_top__mmap_read(top);
 
@@ -991,7 +991,7 @@
 		perf_top__mmap_read(top);
 
 		if (hits == top->samples)
-			ret = poll(top->evlist->pollfd, top->evlist->nr_fds, 100);
+			ret = perf_evlist__poll(top->evlist, 100);
 	}
 
 	ret = 0;
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index a9e96ff..b8fedf3 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2171,7 +2171,7 @@
 	if (trace->nr_events == before) {
 		int timeout = done ? 100 : -1;
 
-		if (poll(evlist->pollfd, evlist->nr_fds, timeout) > 0)
+		if (perf_evlist__poll(evlist, timeout) > 0)
 			goto again;
 	} else {
 		goto again;
diff --git a/tools/perf/tests/open-syscall-tp-fields.c b/tools/perf/tests/open-syscall-tp-fields.c
index 922bdb6..127dcae 100644
--- a/tools/perf/tests/open-syscall-tp-fields.c
+++ b/tools/perf/tests/open-syscall-tp-fields.c
@@ -105,7 +105,7 @@
 		}
 
 		if (nr_events == before)
-			poll(evlist->pollfd, evlist->nr_fds, 10);
+			perf_evlist__poll(evlist, 10);
 
 		if (++nr_polls > 5) {
 			pr_debug("%s: no events!\n", __func__);
diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
index 2ce753c..7a228a2 100644
--- a/tools/perf/tests/perf-record.c
+++ b/tools/perf/tests/perf-record.c
@@ -268,7 +268,7 @@
 		 * perf_event_attr.wakeup_events, just PERF_EVENT_SAMPLE does.
 		 */
 		if (total_events == before && false)
-			poll(evlist->pollfd, evlist->nr_fds, -1);
+			perf_evlist__poll(evlist, -1);
 
 		sleep(1);
 		if (++wakeups > 5) {
diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c
index 87522f0..3a8fedef 100644
--- a/tools/perf/tests/task-exit.c
+++ b/tools/perf/tests/task-exit.c
@@ -105,7 +105,7 @@
 	}
 
 	if (!exited || !nr_exit) {
-		poll(evlist->pollfd, evlist->nr_fds, -1);
+		perf_evlist__poll(evlist, -1);
 		goto retry;
 	}
 
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index bcf157c..5ff3c66 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -475,6 +475,11 @@
 	return nr_fds;
 }
 
+int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
+{
+	return poll(evlist->pollfd, evlist->nr_fds, timeout);
+}
+
 static void perf_evlist__id_hash(struct perf_evlist *evlist,
 				 struct perf_evsel *evsel,
 				 int cpu, int thread, u64 id)
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index bbc2fd0..d7e99b6 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -87,6 +87,8 @@
 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);
 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask);
 
+int perf_evlist__poll(struct perf_evlist *evlist, int timeout);
+
 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id);
 
 struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id);
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 12aa9b0..4472f8b 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -736,7 +736,7 @@
 	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|i", kwlist, &timeout))
 		return NULL;
 
-	n = poll(evlist->pollfd, evlist->nr_fds, timeout);
+	n = perf_evlist__poll(evlist, timeout);
 	if (n < 0) {
 		PyErr_SetFromErrno(PyExc_OSError);
 		return NULL;