perf ftrace: Use atomic inc to update histogram in BPF

It should use an atomic instruction to update even if the histogram is
keyed by delta as it's also used for stats.

Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20250227191223.1288473-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/util/bpf_skel/func_latency.bpf.c b/tools/perf/util/bpf_skel/func_latency.bpf.c
index ad70547446786c54a9b8090d975a34542984517f..e731a79a753a4d2d524f77151a071e0ca8473aaa 100644 (file)
--- a/tools/perf/util/bpf_skel/func_latency.bpf.c
+++ b/tools/perf/util/bpf_skel/func_latency.bpf.c
@@ -142,7 +142,7 @@ do_lookup:
                if (!hist)
                        return 0;
 
-               *hist += 1;
+               __sync_fetch_and_add(hist, 1);
 
                __sync_fetch_and_add(&total, delta); // always in nsec
                __sync_fetch_and_add(&count, 1);