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>
diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
new file mode 100644
index 0000000..84470ed
--- /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;
+}