diff options
Diffstat (limited to 'tools/perf/util/smt.c')
| -rw-r--r-- | tools/perf/util/smt.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/tools/perf/util/smt.c b/tools/perf/util/smt.c index 3b791ef2cd50..20bacd5972ad 100644 --- a/tools/perf/util/smt.c +++ b/tools/perf/util/smt.c @@ -15,6 +15,9 @@ int smt_on(void) if (cached) return cached_result; + if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) > 0) + goto done; + ncpu = sysconf(_SC_NPROCESSORS_CONF); for (cpu = 0; cpu < ncpu; cpu++) { unsigned long long siblings; @@ -24,13 +27,13 @@ int smt_on(void) snprintf(fn, sizeof fn, "devices/system/cpu/cpu%d/topology/core_cpus", cpu); - if (access(fn, F_OK) == -1) { + if (sysfs__read_str(fn, &str, &strlen) < 0) { snprintf(fn, sizeof fn, "devices/system/cpu/cpu%d/topology/thread_siblings", cpu); + if (sysfs__read_str(fn, &str, &strlen) < 0) + continue; } - if (sysfs__read_str(fn, &str, &strlen) < 0) - continue; /* Entry is hex, but does not have 0x, so need custom parser */ siblings = strtoull(str, NULL, 16); free(str); @@ -42,6 +45,7 @@ int smt_on(void) } if (!cached) { cached_result = 0; +done: cached = true; } return cached_result; |