From: Namhyung Kim <namhyung@kernel.org>
Date: Sat, 18 Feb 2023 16:27:24 +0000 (-0800)
Subject: perf test: Fix offcpu test prev_state check
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7c0631d494b95fa5697d297ae443d7787321b5a1;p=linux.git

perf test: Fix offcpu test prev_state check

On Fedora 36, the 'perf record' offcpu profiling tests are failing.  It

was because the BPF checks the prev task's state being S or D but
actually it has more bits set.  Let's check the LSB 8 bits for the
purpose of offcpu profiling.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230218162724.1292657-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/bpf_skel/off_cpu.bpf.c b/tools/perf/util/bpf_skel/off_cpu.bpf.c
index 38e3b287dbb22..d877a0a9731f9 100644
--- a/tools/perf/util/bpf_skel/off_cpu.bpf.c
+++ b/tools/perf/util/bpf_skel/off_cpu.bpf.c
@@ -277,7 +277,7 @@ int on_switch(u64 *ctx)
 	else
 		prev_state = get_task_state(prev);
 
-	return off_cpu_stat(ctx, prev, next, prev_state);
+	return off_cpu_stat(ctx, prev, next, prev_state & 0xff);
 }
 
 char LICENSE[] SEC("license") = "Dual BSD/GPL";