Commit 2a220bc9 authored Aug 01, 2019 by Peter Zijlstra Committed by Suren Baghdasaryan Sep 19, 2019

UPSTREAM: sched/psi: Reduce psimon FIFO priority



PSI defaults to a FIFO-99 thread, reduce this to FIFO-1.

FIFO-99 is the very highest priority available to SCHED_FIFO and
it not a suitable default; it would indicate the psi work is the
most important work on the machine.

Since Real-Time tasks will have pre-allocated memory and locked it in
place, Real-Time tasks do not care about PSI. All it needs is to be
above OTHER.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

(cherry picked from commit 14f5c7b46a41a595fc61db37f55721714729e59e)

Bug: 141131229
Test: lmkd_unit_test and ACT mempressure tests
Change-Id: I52964915467577bfc3543700aec9b463f6f0ffe1
Signed-off-by: Suren Baghdasaryan <surenb@google.com>

parent a6af01ed

kernel/sched/psi.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1051,7 +1051,7 @@ struct psi_trigger psi_trigger_create(struct psi_group group,

		if (!rcu_access_pointer(group->poll_kworker)) {
		struct sched_param param = {
		.sched_priority = MAX_RT_PRIO - 1,
		.sched_priority = 1,
		};
		struct kthread_worker *kworker;