linux/tools/perf/tests/topology.c
Jan Stancek da8a58b56c perf tools: Replace _SC_NPROCESSORS_CONF with max_present_cpu in cpu_topology_map
There are 2 problems wrt. cpu_topology_map on systems with sparse CPUs:

1. offline/absent CPUs will have their socket_id and core_id set to -1
   which triggers:
   "socket_id number is too big.You may need to upgrade the perf tool."

2. size of cpu_topology_map (perf_env.cpu[]) is allocated based on
   _SC_NPROCESSORS_CONF, but can be indexed with CPU ids going above.
   Users of perf_env.cpu[] are using CPU id as index. This can lead
   to read beyond what was allocated:
   ==19991== Invalid read of size 4
   ==19991==    at 0x490CEB: check_cpu_topology (topology.c:69)
   ==19991==    by 0x490CEB: test_session_topology (topology.c:106)
   ...

For example:
  _SC_NPROCESSORS_CONF == 16
  available: 2 nodes (0-1)
  node 0 cpus: 0 6 8 10 16 22 24 26
  node 0 size: 12004 MB
  node 0 free: 9470 MB
  node 1 cpus: 1 7 9 11 23 25 27
  node 1 size: 12093 MB
  node 1 free: 9406 MB
  node distances:
  node   0   1
    0:  10  20
    1:  20  10

This patch changes HEADER_NRCPUS.nr_cpus_available from _SC_NPROCESSORS_CONF
to max_present_cpu and updates any user of cpu_topology_map to iterate
with nr_cpus_avail.

As a consequence HEADER_CPU_TOPOLOGY core_id and socket_id lists get longer,
but maintain compatibility with pre-patch state - index to cpu_topology_map is
CPU id.

  perf test 36 -v
  36: Session topology                           :
  --- start ---
  test child forked, pid 22211
  templ file: /tmp/perf-test-gmdX5i
  CPU 0, core 0, socket 0
  CPU 1, core 0, socket 1
  CPU 6, core 10, socket 0
  CPU 7, core 10, socket 1
  CPU 8, core 1, socket 0
  CPU 9, core 1, socket 1
  CPU 10, core 9, socket 0
  CPU 11, core 9, socket 1
  CPU 16, core 0, socket 0
  CPU 22, core 10, socket 0
  CPU 23, core 10, socket 1
  CPU 24, core 1, socket 0
  CPU 25, core 1, socket 1
  CPU 26, core 9, socket 0
  CPU 27, core 9, socket 1
  test child finished with 0
  ---- end ----
  Session topology: Ok

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/d7c05c6445fca74a8442c2c73cfffd349c52c44f.1487146877.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-02-17 12:56:35 -03:00

118 lines
2.4 KiB
C

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "tests.h"
#include "util.h"
#include "session.h"
#include "evlist.h"
#include "debug.h"
#define TEMPL "/tmp/perf-test-XXXXXX"
#define DATA_SIZE 10
static int get_temp(char *path)
{
int fd;
strcpy(path, TEMPL);
fd = mkstemp(path);
if (fd < 0) {
perror("mkstemp failed");
return -1;
}
close(fd);
return 0;
}
static int session_write_header(char *path)
{
struct perf_session *session;
struct perf_data_file file = {
.path = path,
.mode = PERF_DATA_MODE_WRITE,
};
session = perf_session__new(&file, false, NULL);
TEST_ASSERT_VAL("can't get session", session);
session->evlist = perf_evlist__new_default();
TEST_ASSERT_VAL("can't get evlist", session->evlist);
perf_header__set_feat(&session->header, HEADER_CPU_TOPOLOGY);
perf_header__set_feat(&session->header, HEADER_NRCPUS);
session->header.data_size += DATA_SIZE;
TEST_ASSERT_VAL("failed to write header",
!perf_session__write_header(session, session->evlist, file.fd, true));
perf_session__delete(session);
return 0;
}
static int check_cpu_topology(char *path, struct cpu_map *map)
{
struct perf_session *session;
struct perf_data_file file = {
.path = path,
.mode = PERF_DATA_MODE_READ,
};
int i;
session = perf_session__new(&file, false, NULL);
TEST_ASSERT_VAL("can't get session", session);
for (i = 0; i < session->header.env.nr_cpus_avail; i++) {
if (!cpu_map__has(map, i))
continue;
pr_debug("CPU %d, core %d, socket %d\n", i,
session->header.env.cpu[i].core_id,
session->header.env.cpu[i].socket_id);
}
for (i = 0; i < map->nr; i++) {
TEST_ASSERT_VAL("Core ID doesn't match",
(session->header.env.cpu[map->map[i]].core_id == (cpu_map__get_core(map, i, NULL) & 0xffff)));
TEST_ASSERT_VAL("Socket ID doesn't match",
(session->header.env.cpu[map->map[i]].socket_id == cpu_map__get_socket(map, i, NULL)));
}
perf_session__delete(session);
return 0;
}
int test_session_topology(int subtest __maybe_unused)
{
char path[PATH_MAX];
struct cpu_map *map;
int ret = -1;
TEST_ASSERT_VAL("can't get templ file", !get_temp(path));
pr_debug("templ file: %s\n", path);
if (session_write_header(path))
goto free_path;
map = cpu_map__new(NULL);
if (map == NULL) {
pr_debug("failed to get system cpumap\n");
goto free_path;
}
if (check_cpu_topology(path, map))
goto free_map;
ret = 0;
free_map:
cpu_map__put(map);
free_path:
unlink(path);
return ret;
}