This is a note to let you know that I've just added the patch titled kfence: unconditionally use unbound work queue to the 5.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kfence-unconditionally-use-unbound-work-queue.patch and it can be found in the queue-5.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dd641a3601ea14bdef6bf86ac13c80d5faa9aa3b Author: Marco Elver <elver@xxxxxxxxxx> Date: Wed Jun 30 18:54:03 2021 -0700 kfence: unconditionally use unbound work queue [ Upstream commit ff06e45d3aace3f93d23956c1e655224f363ebe2 ] 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> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 4d21ac44d5d3..d7666ace9d2e 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -636,7 +636,7 @@ static void toggle_allocation_gate(struct work_struct *work) /* 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));