sched: Add WF_TTWU, WF_EXEC wakeup flags (17770579) · Commits · 戴 / test

To remove the sd_flag parameter of select_task_rq(), we need another way of encoding wakeup types. There already is a WF_FORK flag, add the missing two. With that said, we still need an easy way to turn WF_foo into SD_bar (e.g. WF_TTWU into SD_BALANCE_WAKE). As suggested by Peter, let's make our lives easier and make them match exactly, and throw in some compile-time checks for good measure. Signed-off-by:

Valentin Schneider <valentin.schneider@arm.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201102184514.2733-2-valentin.schneider@arm.com

kernel/sched/sched.h

+14 −7

Original line number	Diff line number	Diff line
		@@ -1744,13 +1744,20 @@ static inline int task_on_rq_migrating(struct task_struct *p)
		return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING;
		}

		/*
		* wake flags
		*/
		#define WF_SYNC 0x01 /* Waker goes to sleep after wakeup */
		#define WF_FORK 0x02 /* Child wakeup after fork */
		#define WF_MIGRATED 0x04 /* Internal use, task got migrated */
		#define WF_ON_CPU 0x08 /* Wakee is on_cpu */
		/* Wake flags. The first three directly map to some SD flag value */
		#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */
		#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */
		#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */

		#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */
		#define WF_MIGRATED 0x20 /* Internal use, task got migrated */
		#define WF_ON_CPU 0x40 /* Wakee is on_cpu */

		#ifdef CONFIG_SMP
		static_assert(WF_EXEC == SD_BALANCE_EXEC);
		static_assert(WF_FORK == SD_BALANCE_FORK);
		static_assert(WF_TTWU == SD_BALANCE_WAKE);
		#endif

		/*
		* To aid in avoiding the subversion of "niceness" due to uneven distribution

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