From: Marco Elver <elver@xxxxxxxxxx> 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/20210421105132.3965998-4-elver@xxxxxxxxxx Signed-off-by: Marco Elver <elver@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Hillf Danton <hdanton@xxxxxxxx> Cc: Jann Horn <jannh@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kfence/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- 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)); _
