UPSTREAM: 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@google.com
Fixes: 36f0b35d0894 ("kfence: use power-efficient work queue to run delayed work")
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Hillf Danton <hdanton@sina.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ff06e45d3aace3f93d23956c1e655224f363ebe2)
Bug: 187129171
Signed-off-by: Connor O'Brien <connoro@google.com>
Change-Id: Ib0f1a18a42b71e57e8ec095be0b72bd298e8aec5
This commit is contained in:
Marco Elver 2021-06-30 18:54:03 -07:00 • committed by Michael Bestas
commit fd26c6ba53
No known key found for this signature in database
GPG key ID: CC95044519BE6669

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@ -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));