From: Marco Elver <elver@xxxxxxxxxx> Subject: kfence: unconditionally use unbound work queue Unconditionally use unbound work queue, and not just if wq_power_efficient is true. Because if the system is idle, KFENCE may wait, and by being run on the unbound work queue, we permit the scheduler to make better scheduling decisions and not require pinning KFENCE to the same CPU upon waking up. Link: https://lkml.kernel.org/r/20210521111630.472579-1-elver@xxxxxxxxxx Fixes: 36f0b35d0894 ("kfence: use power-efficient work queue to run delayed work") Signed-off-by: Marco Elver <elver@xxxxxxxxxx> Reported-by: Hillf Danton <hdanton@xxxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kfence/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/kfence/core.c~kfence-unconditionally-use-unbound-work-queue +++ a/mm/kfence/core.c @@ -636,7 +636,7 @@ static void toggle_allocation_gate(struc /* Disable static key and reset timer. */ static_branch_disable(&kfence_allocation_key); #endif - queue_delayed_work(system_power_efficient_wq, &kfence_timer, + queue_delayed_work(system_unbound_wq, &kfence_timer, msecs_to_jiffies(kfence_sample_interval)); } static DECLARE_DELAYED_WORK(kfence_timer, toggle_allocation_gate); @@ -666,7 +666,7 @@ void __init kfence_init(void) } WRITE_ONCE(kfence_enabled, true); - queue_delayed_work(system_power_efficient_wq, &kfence_timer, 0); + queue_delayed_work(system_unbound_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)); _
