Commit 36f0b35d authored by Marco Elver's avatar Marco Elver Committed by Linus Torvalds
Browse files

kfence: use power-efficient work queue to run delayed work 

Use the power-efficient work queue, to avoid the pathological case where
we keep pinning ourselves on the same possibly idle CPU on systems that
want to be power-efficient (https://lwn.net/Articles/731052/).

Link: https://lkml.kernel.org/r/20210421105132.3965998-4-elver@google.com


Signed-off-by: default avatarMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 37c9284f

mm/kfence/core.c

+3 −2
Original line number Diff line number Diff line
@@ -636,7 +636,8 @@ static void toggle_allocation_gate(struct work_struct *work) 
	/* Disable static key and reset timer. */

	static_branch_disable(&kfence_allocation_key);

#endif

	schedule_delayed_work(&kfence_timer, msecs_to_jiffies(kfence_sample_interval));

	queue_delayed_work(system_power_efficient_wq, &kfence_timer,

			   msecs_to_jiffies(kfence_sample_interval));

}

static DECLARE_DELAYED_WORK(kfence_timer, toggle_allocation_gate);
@@ -665,7 +666,7 @@ void __init kfence_init(void) 
	}



	WRITE_ONCE(kfence_enabled, true);

	schedule_delayed_work(&kfence_timer, 0);

	queue_delayed_work(system_power_efficient_wq, &kfence_timer, 0);

	pr_info("initialized - using %lu bytes for %d objects at 0x%p-0x%p\n", KFENCE_POOL_SIZE,

		CONFIG_KFENCE_NUM_OBJECTS, (void *)__kfence_pool,

		(void *)(__kfence_pool + KFENCE_POOL_SIZE));