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| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2020-04-29 19:19:47 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-05-05 16:35:29 -0300 |
| commit | 846de4371fdfddfa49481e3d04884539870dc127 (patch) | |
| tree | 19c152a5d5cc8bdf4124bdf320f30d7bbe1476df /tools/perf/util/smt.c | |
| parent | 4599d292128d89e4cf866a0ea9a9b047a2de8418 (diff) | |
| download | linux-846de4371fdfddfa49481e3d04884539870dc127.tar.gz linux-846de4371fdfddfa49481e3d04884539870dc127.tar.bz2 linux-846de4371fdfddfa49481e3d04884539870dc127.zip | |
perf tools: Fix reading new topology attribute "core_cpus"
Check if access("devices/system/cpu/cpu%d/topology/core_cpus", F_OK)
fails, which will happen unless the current directory is "/sys".
Simply try to read this file first.
Fixes: 0ccdb8407a46 ("perf tools: Apply new CPU topology sysfs attributes")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/158817718710.747528.11009278875028211991.stgit@buzz
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/smt.c')
| -rw-r--r-- | tools/perf/util/smt.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/perf/util/smt.c b/tools/perf/util/smt.c index 3b791ef2cd50..8481842e9edb 100644 --- a/tools/perf/util/smt.c +++ b/tools/perf/util/smt.c @@ -24,13 +24,13 @@ 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); |