From f72dbeced286b34e50ea67a3e016e07174febfff Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Thu, 22 Apr 2021 16:42:53 +1000 Subject: [PATCH] FROMGIT: 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: Marco Elver Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Hillf Danton Cc: Jann Horn Cc: Mark Rutland Signed-off-by: Andrew Morton Signed-off-by: Stephen Rothwell Bug: 172317151 Bug: 185280916 Test: power team confirmed there's no regression (cherry picked from commit e5bcc059aa2321383325e98628d65258bdcb306f https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm) Signed-off-by: Alexander Potapenko Change-Id: I53a2869987cdac165840e3878ff73735a03438fa --- mm/kfence/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 9742649f3f88..e18fbbd5d9b4 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -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));