kernel: sched: sleep: Use value returned by z_add_timeout (66daaf6b) · Commits · Wenxi XU / zephyr

z_tick_sleep function needs to calculate expected wakeup tick. It required reading current system clock tick. It can be costly since it is a register access. When timeout is added this value is calculated and z_add_timeout returns it. It can be used instead to optimize sleep performance. Signed-off-by:

Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

kernel/sched.c

+1 −7

Changes for kernel/sched.c: 1 added line, 7 removed lines.
Original line number	Diff line number	Diff line
		@@ -1091,19 +1091,13 @@ static int32_t z_tick_sleep(k_timeout_t timeout)
		return 0;
		}

		if (Z_IS_TIMEOUT_RELATIVE(timeout)) {
		expected_wakeup_ticks = timeout.ticks + sys_clock_tick_get_32();
		} else {
		expected_wakeup_ticks = Z_TICK_ABS(timeout.ticks);
		}

		k_spinlock_key_t key = k_spin_lock(&_sched_spinlock);

		#if defined(CONFIG_TIMESLICING) && defined(CONFIG_SWAP_NONATOMIC)
		pending_current = _current;
		#endif /* CONFIG_TIMESLICING && CONFIG_SWAP_NONATOMIC */
		unready_thread(_current);
		z_add_thread_timeout(_current, timeout);
		expected_wakeup_ticks = (uint32_t)z_add_thread_timeout(_current, timeout);
		z_mark_thread_as_sleeping(_current);

		(void)z_swap(&_sched_spinlock, key);

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