kernel: Re-order should_preempt() checks (0bf44f23) · Commits · Wenxi XU / zephyr

Re-orders the checks in should_preempt() tests so that the z_is_thread_timeout_active() check is done last. This change has been observed to give a +7% performance boost on the thread_metric benchmark's preemptive scheduling test. Signed-off-by:

Peter Mitsis <peter.mitsis@intel.com>

kernel/include/kthread.h

+7 −7

Original line number	Diff line number	Diff line
		@@ -204,6 +204,13 @@ static ALWAYS_INLINE bool should_preempt(struct k_thread *thread,
		return true;
		}

		/* Otherwise we have to be running a preemptible thread or
		* switching to a metairq
		*/
		if (thread_is_preemptible(_current) \|\| thread_is_metairq(thread)) {
		return true;
		}

		/* Edge case on ARM where a thread can be pended out of an
		* interrupt handler before the "synchronous" swap starts
		* context switching. Platforms with atomic swap can never
		@@ -214,13 +221,6 @@ static ALWAYS_INLINE bool should_preempt(struct k_thread *thread,
		return true;
		}

		/* Otherwise we have to be running a preemptible thread or
		* switching to a metairq
		*/
		if (thread_is_preemptible(_current) \|\| thread_is_metairq(thread)) {
		return true;
		}

		return false;
		}

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