perf evlist: Store pointer to the cpu and thread maps

So that we don't have to pass it around to the several methods that
needs it, simplifying usage.

There is one case where we don't have the thread/cpu map in advance,
which is in the parsing routines used by top, stat, record, that we have
to wait till all options are parsed to know if a cpu or thread list was
passed to then create those maps.

For that case consolidate the cpu and thread map creation via
perf_evlist__create_maps() out of the code in top and record, while also
providing a perf_evlist__set_maps() for cases where multiple evlists
share maps or for when maps that represent CPU sockets, for instance,
get crafted out of topology information or subsets of threads in a
particular application are to be monitored, providing more granularity
in specifying which cpus and threads to monitor.

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>

3 files changed, 86 insertions, 35 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index dcd5932..95b21fe 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -21,21 +21,24 @@
 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
 #define SID(e, x, y) xyarray__entry(e->id, x, y)
 
-void perf_evlist__init(struct perf_evlist *evlist)
+void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
+		       struct thread_map *threads)
 {
 	int i;
 
 	for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
 		INIT_HLIST_HEAD(&evlist->heads[i]);
 	INIT_LIST_HEAD(&evlist->entries);
+	perf_evlist__set_maps(evlist, cpus, threads);
 }
 
-struct perf_evlist *perf_evlist__new(void)
+struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
+				     struct thread_map *threads)
 {
 	struct perf_evlist *evlist = zalloc(sizeof(*evlist));
 
 	if (evlist != NULL)
-		perf_evlist__init(evlist);
+		perf_evlist__init(evlist, cpus, threads);
 
 	return evlist;
 }
@@ -88,9 +91,9 @@ int perf_evlist__add_default(struct perf_evlist *evlist)
 	return 0;
 }
 
-int perf_evlist__alloc_pollfd(struct perf_evlist *evlist, int ncpus, int nthreads)
+int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 {
-	int nfds = ncpus * nthreads * evlist->nr_entries;
+	int nfds = evlist->cpus->nr * evlist->threads->nr * evlist->nr_entries;
 	evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
 	return evlist->pollfd != NULL ? 0 : -ENOMEM;
 }
@@ -213,11 +216,11 @@ union perf_event *perf_evlist__read_on_cpu(struct perf_evlist *evlist, int cpu)
 	return event;
 }
 
-void perf_evlist__munmap(struct perf_evlist *evlist, int ncpus)
+void perf_evlist__munmap(struct perf_evlist *evlist)
 {
 	int cpu;
 
-	for (cpu = 0; cpu < ncpus; cpu++) {
+	for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
 		if (evlist->mmap[cpu].base != NULL) {
 			munmap(evlist->mmap[cpu].base, evlist->mmap_len);
 			evlist->mmap[cpu].base = NULL;
@@ -225,9 +228,9 @@ void perf_evlist__munmap(struct perf_evlist *evlist, int ncpus)
 	}
 }
 
-int perf_evlist__alloc_mmap(struct perf_evlist *evlist, int ncpus)
+int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
 {
-	evlist->mmap = zalloc(ncpus * sizeof(struct perf_mmap));
+	evlist->mmap = zalloc(evlist->cpus->nr * sizeof(struct perf_mmap));
 	return evlist->mmap != NULL ? 0 : -ENOMEM;
 }
 
@@ -248,8 +251,6 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int cpu, int prot,
 /** perf_evlist__mmap - Create per cpu maps to receive events
  *
  * @evlist - list of events
- * @cpus - cpu map being monitored
- * @threads - threads map being monitored
  * @pages - map length in pages
  * @overwrite - overwrite older events?
  *
@@ -259,21 +260,22 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int cpu, int prot,
  *	unsigned int head = perf_mmap__read_head(m);
  *
  *	perf_mmap__write_tail(m, head)
+ *
+ * Using perf_evlist__read_on_cpu does this automatically.
  */
-int perf_evlist__mmap(struct perf_evlist *evlist, struct cpu_map *cpus,
-		      struct thread_map *threads, int pages, bool overwrite)
+int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite)
 {
 	unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 	int mask = pages * page_size - 1, cpu;
 	struct perf_evsel *first_evsel, *evsel;
+	const struct cpu_map *cpus = evlist->cpus;
+	const struct thread_map *threads = evlist->threads;
 	int thread, prot = PROT_READ | (overwrite ? 0 : PROT_WRITE);
 
-	if (evlist->mmap == NULL &&
-	    perf_evlist__alloc_mmap(evlist, cpus->nr) < 0)
+	if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
 		return -ENOMEM;
 
-	if (evlist->pollfd == NULL &&
-	    perf_evlist__alloc_pollfd(evlist, cpus->nr, threads->nr) < 0)
+	if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
 		return -ENOMEM;
 
 	evlist->overwrite = overwrite;
@@ -315,3 +317,34 @@ out_unmap:
 	}
 	return -1;
 }
+
+int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
+			     pid_t target_tid, const char *cpu_list)
+{
+	evlist->threads = thread_map__new(target_pid, target_tid);
+
+	if (evlist->threads == NULL)
+		return -1;
+
+	if (target_tid != -1)
+		evlist->cpus = cpu_map__dummy_new();
+	else
+		evlist->cpus = cpu_map__new(cpu_list);
+
+	if (evlist->cpus == NULL)
+		goto out_delete_threads;
+
+	return 0;
+
+out_delete_threads:
+	thread_map__delete(evlist->threads);
+	return -1;
+}
+
+void perf_evlist__delete_maps(struct perf_evlist *evlist)
+{
+	cpu_map__delete(evlist->cpus);
+	thread_map__delete(evlist->threads);
+	evlist->cpus	= NULL;
+	evlist->threads = NULL;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 85aca6e..c988405 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -22,28 +22,43 @@ struct perf_evlist {
 	union perf_event event_copy;
 	struct perf_mmap *mmap;
 	struct pollfd	 *pollfd;
+	struct thread_map *threads;
+	struct cpu_map	  *cpus;
 };
 
 struct perf_evsel;
 
-struct perf_evlist *perf_evlist__new(void);
-void perf_evlist__init(struct perf_evlist *evlist);
+struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
+				     struct thread_map *threads);
+void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
+		       struct thread_map *threads);
 void perf_evlist__exit(struct perf_evlist *evlist);
 void perf_evlist__delete(struct perf_evlist *evlist);
 
 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry);
 int perf_evlist__add_default(struct perf_evlist *evlist);
 
-int perf_evlist__alloc_pollfd(struct perf_evlist *evlist, int ncpus, int nthreads);
+int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);
 void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd);
 
 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id);
 
 union perf_event *perf_evlist__read_on_cpu(struct perf_evlist *self, int cpu);
 
-int perf_evlist__alloc_mmap(struct perf_evlist *evlist, int ncpus);
-int perf_evlist__mmap(struct perf_evlist *evlist, struct cpu_map *cpus,
-		      struct thread_map *threads, int pages, bool overwrite);
-void perf_evlist__munmap(struct perf_evlist *evlist, int ncpus);
+int perf_evlist__alloc_mmap(struct perf_evlist *evlist);
+int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite);
+void perf_evlist__munmap(struct perf_evlist *evlist);
+
+static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
+					 struct cpu_map *cpus,
+					 struct thread_map *threads)
+{
+	evlist->cpus	= cpus;
+	evlist->threads	= threads;
+}
+
+int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
+			     pid_t target_tid, const char *cpu_list);
+void perf_evlist__delete_maps(struct perf_evlist *evlist);
 
 #endif /* __PERF_EVLIST_H */
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 88d4789..d2d5217 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -553,7 +553,16 @@ struct pyrf_evlist {
 static int pyrf_evlist__init(struct pyrf_evlist *pevlist,
 			     PyObject *args, PyObject *kwargs)
 {
-	perf_evlist__init(&pevlist->evlist);
+	PyObject *pcpus = NULL, *pthreads = NULL;
+	struct cpu_map *cpus;
+	struct thread_map *threads;
+
+	if (!PyArg_ParseTuple(args, "OO", &pcpus, &pthreads))
+		return -1;
+
+	threads = ((struct pyrf_thread_map *)pthreads)->threads;
+	cpus = ((struct pyrf_cpu_map *)pcpus)->cpus;
+	perf_evlist__init(&pevlist->evlist, cpus, threads);
 	return 0;
 }
 
@@ -567,21 +576,15 @@ static PyObject *pyrf_evlist__mmap(struct pyrf_evlist *pevlist,
 				   PyObject *args, PyObject *kwargs)
 {
 	struct perf_evlist *evlist = &pevlist->evlist;
-	PyObject *pcpus = NULL, *pthreads = NULL;
-	struct cpu_map *cpus = NULL;
-	struct thread_map *threads = NULL;
-	static char *kwlist[] = {"cpus", "threads", "pages", "overwrite",
+	static char *kwlist[] = {"pages", "overwrite",
 				  NULL, NULL};
 	int pages = 128, overwrite = false;
 
-	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "OO|ii", kwlist,
-					 &pcpus, &pthreads, &pages, &overwrite))
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|ii", kwlist,
+					 &pages, &overwrite))
 		return NULL;
 
-	threads = ((struct pyrf_thread_map *)pthreads)->threads;
-	cpus = ((struct pyrf_cpu_map *)pcpus)->cpus;
-
-	if (perf_evlist__mmap(evlist, cpus, threads, pages, overwrite) < 0) {
+	if (perf_evlist__mmap(evlist, pages, overwrite) < 0) {
 		PyErr_SetFromErrno(PyExc_OSError);
 		return NULL;
 	}