diff options
author | Jan Stancek <jstancek@redhat.com> | 2017-02-17 14:10:26 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-02-17 18:56:35 +0300 |
commit | da8a58b56c661681f9b2fd2fa59c6da3a5bac8d1 (patch) | |
tree | 6c3d7be2c88dd61e006831715244fccf951cf35f /tools | |
parent | 43db2843a4a41cc8cdb6ab696639aeee1f4d5062 (diff) | |
download | linux-da8a58b56c661681f9b2fd2fa59c6da3a5bac8d1.tar.xz |
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>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/perf/builtin-stat.c | 2 | ||||
-rw-r--r-- | tools/perf/tests/topology.c | 4 | ||||
-rw-r--r-- | tools/perf/util/env.c | 2 | ||||
-rw-r--r-- | tools/perf/util/header.c | 16 |
4 files changed, 10 insertions, 14 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index f28719178b51..ca27a8a705ac 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -1765,7 +1765,7 @@ static inline int perf_env__get_cpu(struct perf_env *env, struct cpu_map *map, i cpu = map->map[idx]; - if (cpu >= env->nr_cpus_online) + if (cpu >= env->nr_cpus_avail) return -1; return cpu; diff --git a/tools/perf/tests/topology.c b/tools/perf/tests/topology.c index 98fe69ac553c..803f893550d6 100644 --- a/tools/perf/tests/topology.c +++ b/tools/perf/tests/topology.c @@ -65,7 +65,9 @@ static int check_cpu_topology(char *path, struct cpu_map *map) session = perf_session__new(&file, false, NULL); TEST_ASSERT_VAL("can't get session", session); - for (i = 0; i < session->header.env.nr_cpus_online; i++) { + 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); diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c index bb964e86b09d..075fc77286bf 100644 --- a/tools/perf/util/env.c +++ b/tools/perf/util/env.c @@ -66,7 +66,7 @@ int perf_env__read_cpu_topology_map(struct perf_env *env) return 0; if (env->nr_cpus_avail == 0) - env->nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF); + env->nr_cpus_avail = cpu__max_present_cpu(); nr_cpus = env->nr_cpus_avail; if (nr_cpus == -1) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 1222f6c5e7b3..05714d548584 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -295,11 +295,7 @@ static int write_nrcpus(int fd, struct perf_header *h __maybe_unused, u32 nrc, nra; int ret; - nr = sysconf(_SC_NPROCESSORS_CONF); - if (nr < 0) - return -1; - - nrc = (u32)(nr & UINT_MAX); + nrc = cpu__max_present_cpu(); nr = sysconf(_SC_NPROCESSORS_ONLN); if (nr < 0) @@ -513,9 +509,7 @@ static struct cpu_topo *build_cpu_topology(void) int ret = -1; struct cpu_map *map; - ncpus = sysconf(_SC_NPROCESSORS_CONF); - if (ncpus < 0) - return NULL; + ncpus = cpu__max_present_cpu(); /* build online CPU map */ map = cpu_map__new(NULL); @@ -1139,7 +1133,7 @@ static void print_cpu_topology(struct perf_header *ph, int fd __maybe_unused, { int nr, i; char *str; - int cpu_nr = ph->env.nr_cpus_online; + int cpu_nr = ph->env.nr_cpus_avail; nr = ph->env.nr_sibling_cores; str = ph->env.sibling_cores; @@ -1794,7 +1788,7 @@ static int process_cpu_topology(struct perf_file_section *section, u32 nr, i; char *str; struct strbuf sb; - int cpu_nr = ph->env.nr_cpus_online; + int cpu_nr = ph->env.nr_cpus_avail; u64 size = 0; ph->env.cpu = calloc(cpu_nr, sizeof(*ph->env.cpu)); @@ -1875,7 +1869,7 @@ static int process_cpu_topology(struct perf_file_section *section, if (ph->needs_swap) nr = bswap_32(nr); - if (nr > (u32)cpu_nr) { + if (nr != (u32)-1 && nr > (u32)cpu_nr) { pr_debug("socket_id number is too big." "You may need to upgrade the perf tool.\n"); goto free_cpu; |