From b205bb2589f3ac516c440f2eded45851ebb494b0 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 6 Oct 2021 13:18:49 +0200
Subject: [PATCH 052/158] sched/rt: Annotate the RT balancing logic irqwork as
 IRQ_WORK_HARD_IRQ

The push-IPI logic for RT tasks expects to be invoked from hardirq
context. One reason is that a RT task on the remote CPU would block the
softirq processing on PREEMPT_RT and so avoid pulling / balancing the RT
tasks as intended.

Annotate root_domain::rto_push_work as IRQ_WORK_HARD_IRQ.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20211006111852.1514359-2-bigeasy@linutronix.de
---
 kernel/sched/topology.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-5.15/kernel/sched/topology.c
===================================================================
--- linux-5.15.orig/kernel/sched/topology.c
+++ linux-5.15/kernel/sched/topology.c
@@ -526,7 +526,7 @@ static int init_rootdomain(struct root_d
 #ifdef HAVE_RT_PUSH_IPI
 	rd->rto_cpu = -1;
 	raw_spin_lock_init(&rd->rto_lock);
-	init_irq_work(&rd->rto_push_work, rto_push_irq_work_func);
+	rd->rto_push_work = IRQ_WORK_INIT_HARD(rto_push_irq_work_func);
 #endif
 
 	rd->visit_gen = 0;