tick/nohz: Optimize check_tick_dependency() with early return

There is no point in iterating through individual tick dependency bits when
the tick_stop tracepoint is disabled, which is the common case.

When the trace point is disabled, return immediately based on the atomic
value being zero or non-zero, skipping the per-bit evaluation.

This optimization improves the hot path performance of tick dependency
checks across all contexts (idle and non-idle), not just nohz_full CPUs.

Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ionut Nechita (Sunlight Linux) <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://patch.msgid.link/[email protected]

kernel/time/tick-sched.c

@@ -344,6 +344,9 @@ static bool check_tick_dependency(atomic_t *dep)
 {
 	int val = atomic_read(dep);
 
+	if (likely(!tracepoint_enabled(tick_stop)))
+		return !val;
+
 	if (val & TICK_DEP_MASK_POSIX_TIMER) {
 		trace_tick_stop(0, TICK_DEP_MASK_POSIX_TIMER);
 		return true;