Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b34920d4 authored by Valentin Schneider's avatar Valentin Schneider Committed by Ingo Molnar
Browse files

sched/fair: Move task_numa_work() init to init_numa_balancing() 



We only need to set the callback_head worker function once, do it
during sched_fork().

While at it, move the comment regarding double task_work addition to
init_numa_balancing(), since the double add sentinel is first set there.

Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mgorman@suse.de
Cc: riel@surriel.com
Link: https://lkml.kernel.org/r/20190715102508.32434-3-valentin.schneider@arm.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent d35927a1

kernel/sched/fair.c

+5 −4
Original line number Diff line number Diff line
@@ -2495,7 +2495,7 @@ void task_numa_work(struct callback_head *work) 


	SCHED_WARN_ON(p != container_of(work, struct task_struct, numa_work));



	work->next = work; /* protect against double add */

	work->next = work;

	/*

	 * Who cares about NUMA placement when they're dying.

	 *
@@ -2639,12 +2639,15 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) 
	p->node_stamp			= 0;

	p->numa_scan_seq		= mm ? mm->numa_scan_seq : 0;

	p->numa_scan_period		= sysctl_numa_balancing_scan_delay;

	/* Protect against double add, see task_tick_numa and task_numa_work */

	p->numa_work.next		= &p->numa_work;

	p->numa_faults			= NULL;

	RCU_INIT_POINTER(p->numa_group, NULL);

	p->last_task_numa_placement	= 0;

	p->last_sum_exec_runtime	= 0;



	init_task_work(&p->numa_work, task_numa_work);



	/* New address space, reset the preferred nid */

	if (!(clone_flags & CLONE_VM)) {

		p->numa_preferred_nid = NUMA_NO_NODE;
@@ -2693,12 +2696,10 @@ static void task_tick_numa(struct rq *rq, struct task_struct *curr) 
			curr->numa_scan_period = task_scan_start(curr);

		curr->node_stamp += period;



		if (!time_before(jiffies, curr->mm->numa_next_scan)) {

			init_task_work(work, task_numa_work); /* TODO: move this into sched_fork() */

		if (!time_before(jiffies, curr->mm->numa_next_scan))

			task_work_add(curr, work, true);

	}

}

}



static void update_scan_period(struct task_struct *p, int new_cpu)

{