From: Ian Rogers <irogers@xxxxxxxxxx>
commit 4ffbe87e2d5b53bcb0213d8650bbe70bf942de6a upstream.
sysfs__read_int() returns 0 on success, and so the fast read path was
always failing.
Fixes: bb629484d924118e ("perf tools: Simplify checking if SMT is active.")
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: John Garry <john.garry@xxxxxxxxxx>
Cc: Kajol Jain <kjain@xxxxxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Paul Clarke <pc@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20211124001231.3277836-2-irogers@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/util/smt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/perf/util/smt.c
+++ b/tools/perf/util/smt.c
@@ -15,7 +15,7 @@ int smt_on(void)
if (cached)
return cached_result;
- if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) > 0)
+ if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) >= 0)
goto done;
ncpu = sysconf(_SC_NPROCESSORS_CONF);
