perf tools: Add cpu_topology object

Make struct cpu_topo global and rename it to 'struct cpu_topology', so
that it can be used from the 'perf record' command in the following
patches.

Add the following interface functions to load/free cpu topology details:

  struct cpu_topology *cpu_topology__new(void);
  void cpu_topology__delete(struct cpu_topology *tp);

Move it to a separate source file cputopo.c together with numa related
object in the following patches.

No functional change, the new interface will be used in upcoming changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190219095815.15931-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 144 insertions, 0 deletions

diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
new file mode 100644
index 000000000000..84470ed4e707
--- /dev/null
+++ b/tools/perf/util/cputopo.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <sys/param.h>
+
+#include "cputopo.h"
+#include "cpumap.h"
+#include "util.h"
+
+
+#define CORE_SIB_FMT \
+	"/sys/devices/system/cpu/cpu%d/topology/core_siblings_list"
+#define THRD_SIB_FMT \
+	"/sys/devices/system/cpu/cpu%d/topology/thread_siblings_list"
+
+static int build_cpu_topology(struct cpu_topology *tp, int cpu)
+{
+	FILE *fp;
+	char filename[MAXPATHLEN];
+	char *buf = NULL, *p;
+	size_t len = 0;
+	ssize_t sret;
+	u32 i = 0;
+	int ret = -1;
+
+	sprintf(filename, CORE_SIB_FMT, cpu);
+	fp = fopen(filename, "r");
+	if (!fp)
+		goto try_threads;
+
+	sret = getline(&buf, &len, fp);
+	fclose(fp);
+	if (sret <= 0)
+		goto try_threads;
+
+	p = strchr(buf, '\n');
+	if (p)
+		*p = '\0';
+
+	for (i = 0; i < tp->core_sib; i++) {
+		if (!strcmp(buf, tp->core_siblings[i]))
+			break;
+	}
+	if (i == tp->core_sib) {
+		tp->core_siblings[i] = buf;
+		tp->core_sib++;
+		buf = NULL;
+		len = 0;
+	}
+	ret = 0;
+
+try_threads:
+	sprintf(filename, THRD_SIB_FMT, cpu);
+	fp = fopen(filename, "r");
+	if (!fp)
+		goto done;
+
+	if (getline(&buf, &len, fp) <= 0)
+		goto done;
+
+	p = strchr(buf, '\n');
+	if (p)
+		*p = '\0';
+
+	for (i = 0; i < tp->thread_sib; i++) {
+		if (!strcmp(buf, tp->thread_siblings[i]))
+			break;
+	}
+	if (i == tp->thread_sib) {
+		tp->thread_siblings[i] = buf;
+		tp->thread_sib++;
+		buf = NULL;
+	}
+	ret = 0;
+done:
+	if (fp)
+		fclose(fp);
+	free(buf);
+	return ret;
+}
+
+void cpu_topology__delete(struct cpu_topology *tp)
+{
+	u32 i;
+
+	if (!tp)
+		return;
+
+	for (i = 0 ; i < tp->core_sib; i++)
+		zfree(&tp->core_siblings[i]);
+
+	for (i = 0 ; i < tp->thread_sib; i++)
+		zfree(&tp->thread_siblings[i]);
+
+	free(tp);
+}
+
+struct cpu_topology *cpu_topology__new(void)
+{
+	struct cpu_topology *tp = NULL;
+	void *addr;
+	u32 nr, i;
+	size_t sz;
+	long ncpus;
+	int ret = -1;
+	struct cpu_map *map;
+
+	ncpus = cpu__max_present_cpu();
+
+	/* build online CPU map */
+	map = cpu_map__new(NULL);
+	if (map == NULL) {
+		pr_debug("failed to get system cpumap\n");
+		return NULL;
+	}
+
+	nr = (u32)(ncpus & UINT_MAX);
+
+	sz = nr * sizeof(char *);
+	addr = calloc(1, sizeof(*tp) + 2 * sz);
+	if (!addr)
+		goto out_free;
+
+	tp = addr;
+	addr += sizeof(*tp);
+	tp->core_siblings = addr;
+	addr += sz;
+	tp->thread_siblings = addr;
+
+	for (i = 0; i < nr; i++) {
+		if (!cpu_map__has(map, i))
+			continue;
+
+		ret = build_cpu_topology(tp, i);
+		if (ret < 0)
+			break;
+	}
+
+out_free:
+	cpu_map__put(map);
+	if (ret) {
+		cpu_topology__delete(tp);
+		tp = NULL;
+	}
+	return tp;
+}