[143/143] kfence: use power-efficient work queue to run delayed work

Commit Message

Andrew Morton May 5, 2021, 1:40 a.m. UTC

From: Marco Elver <[e-mail]>
Subject: 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/[e-mail]
Signed-off-by: Marco Elver <[e-mail]>
Cc: Alexander Potapenko <[e-mail]>
Cc: Dmitry Vyukov <[e-mail]>
Cc: Hillf Danton <[e-mail]>
Cc: Jann Horn <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/kfence/core.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Patch

--- a/mm/kfence/core.c~kfence-use-power-efficient-work-queue-to-run-delayed-work
+++ a/mm/kfence/core.c
@@ -636,7 +636,8 @@  static void toggle_allocation_gate(struc
 	/* 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));