From 31cb1bc0dc94882a588930f4d007b570c481fd17 Mon Sep 17 00:00:00 2001 From: rodrigosiqueira Date: Fri, 15 Dec 2017 12:06:03 -0200 Subject: sched/core: Rework and clarify prepare_lock_switch() The prepare_lock_switch() function has an unused parameter, and also the function name was not descriptive. To improve readability and remove the extra parameter, do the following changes: * Move prepare_lock_switch() from kernel/sched/sched.h to kernel/sched/core.c, rename it to prepare_task(), and remove the unused parameter. * Split the smp_store_release() out from finish_lock_switch() to a function named finish_task. * Comments ajdustments. Signed-off-by: Rodrigo Siqueira Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20171215140603.gxe5i2y6fg5ojfpp@smtp.gmail.com Signed-off-by: Ingo Molnar --- kernel/sched/sched.h | 41 ----------------------------------------- 1 file changed, 41 deletions(-) (limited to 'kernel/sched/sched.h') diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index b19552a212de..43f5d6e936bb 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1328,47 +1328,6 @@ static inline int task_on_rq_migrating(struct task_struct *p) # define finish_arch_post_lock_switch() do { } while (0) #endif -static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) -{ -#ifdef CONFIG_SMP - /* - * We can optimise this out completely for !SMP, because the - * SMP rebalancing from interrupt is the only thing that cares - * here. - */ - next->on_cpu = 1; -#endif -} - -static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) -{ -#ifdef CONFIG_SMP - /* - * After ->on_cpu is cleared, the task can be moved to a different CPU. - * We must ensure this doesn't happen until the switch is completely - * finished. - * - * In particular, the load of prev->state in finish_task_switch() must - * happen before this. - * - * Pairs with the smp_cond_load_acquire() in try_to_wake_up(). - */ - smp_store_release(&prev->on_cpu, 0); -#endif -#ifdef CONFIG_DEBUG_SPINLOCK - /* this is a valid case when another task releases the spinlock */ - rq->lock.owner = current; -#endif - /* - * If we are tracking spinlock dependencies then we have to - * fix up the runqueue lock - which gets 'carried over' from - * prev into current: - */ - spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); - - raw_spin_unlock_irq(&rq->lock); -} - /* * wake flags */ -- cgit