libperf: Add perf_evlist__alloc_pollfd() function

Move perf_evlist__alloc_pollfd() from tools/perf to libperf, it will be
used in the following patches.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lore.kernel.org/lkml/20190913132355.21634-37-jolsa@kernel.org
[ Added api/fd/array.h include to the lib/evlist.c file ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/evlist.c

@@ -14,6 +14,7 @@
 #include <unistd.h>
 #include <perf/cpumap.h>
 #include <perf/threadmap.h>
+#include <api/fd/array.h>
 
 void perf_evlist__init(struct perf_evlist *evlist)
 {
@@ -238,3 +239,24 @@ int perf_evlist__id_add_fd(struct perf_evlist *evlist,
 	perf_evlist__id_add(evlist, evsel, cpu, thread, id);
 	return 0;
 }
+
+int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
+{
+	int nr_cpus = perf_cpu_map__nr(evlist->cpus);
+	int nr_threads = perf_thread_map__nr(evlist->threads);
+	int nfds = 0;
+	struct perf_evsel *evsel;
+
+	perf_evlist__for_each_entry(evlist, evsel) {
+		if (evsel->system_wide)
+			nfds += nr_cpus;
+		else
+			nfds += nr_cpus * nr_threads;
+	}
+
+	if (fdarray__available_entries(&evlist->pollfd) < nfds &&
+	    fdarray__grow(&evlist->pollfd, nfds) < 0)
+		return -ENOMEM;
+
+	return 0;
+}

tools/perf/lib/include/internal/evlist.h

@@ -24,6 +24,8 @@ struct perf_evlist {
 	struct hlist_head	 heads[PERF_EVLIST__HLIST_SIZE];
 };
 
+int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);
+
 /**
  * __perf_evlist__for_each_entry - iterate thru all the evsels
  * @list: list_head instance to iterate

tools/perf/util/evlist.c

@@ -398,27 +398,6 @@ int perf_evlist__enable_event_idx(struct evlist *evlist,
 		return perf_evlist__enable_event_thread(evlist, evsel, idx);
 }
 
-int perf_evlist__alloc_pollfd(struct evlist *evlist)
-{
-	int nr_cpus = perf_cpu_map__nr(evlist->core.cpus);
-	int nr_threads = perf_thread_map__nr(evlist->core.threads);
-	int nfds = 0;
-	struct evsel *evsel;
-
-	evlist__for_each_entry(evlist, evsel) {
-		if (evsel->core.system_wide)
-			nfds += nr_cpus;
-		else
-			nfds += nr_cpus * nr_threads;
-	}
-
-	if (fdarray__available_entries(&evlist->core.pollfd) < nfds &&
-	    fdarray__grow(&evlist->core.pollfd, nfds) < 0)
-		return -ENOMEM;
-
-	return 0;
-}
-
 static int __perf_evlist__add_pollfd(struct evlist *evlist, int fd,
 				     struct mmap *map, short revent)
 {
@@ -944,7 +923,7 @@ int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
 	if (!evlist->mmap)
 		return -ENOMEM;
 
-	if (evlist->core.pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
+	if (evlist->core.pollfd.entries == NULL && perf_evlist__alloc_pollfd(&evlist->core) < 0)
 		return -ENOMEM;
 
 	evlist->core.mmap_len = evlist__mmap_size(pages);

tools/perf/util/evlist.h

@@ -142,7 +142,6 @@ perf_evlist__find_tracepoint_by_name(struct evlist *evlist,
 				     const char *name);
 
 int perf_evlist__add_pollfd(struct evlist *evlist, int fd);
-int perf_evlist__alloc_pollfd(struct evlist *evlist);
 int perf_evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask);
 
 int perf_evlist__poll(struct evlist *evlist, int timeout);