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From:   John Keeping <john@metanate.com>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     John Keeping <john@metanate.com>, linux-kernel@vger.kernel.org
Subject: [PATCH] genirq: update affinity of secondary threads
Date:   Thu,  6 Apr 2023 19:08:57 +0100
Message-Id: <20230406180857.588682-1-john@metanate.com>
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For interrupts with secondary threads, the affinity is applied when the
thread is created but if the interrupts affinity is changed later only
the primary thread is updated.

Update the secondary thread's affinity as well to keep all the
interrupt's activity on the assigned CPUs.

Signed-off-by: John Keeping <john@metanate.com>
---
 kernel/irq/manage.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 8ce75495e04f..4f76eb8b7fcf 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -189,9 +189,13 @@ void irq_set_thread_affinity(struct irq_desc *desc)
 {
 	struct irqaction *action;
 
-	for_each_action_of_desc(desc, action)
+	for_each_action_of_desc(desc, action) {
 		if (action->thread)
 			set_bit(IRQTF_AFFINITY, &action->thread_flags);
+		if (action->secondary && action->secondary->thread)
+			set_bit(IRQTF_AFFINITY,
+				&action->secondary->thread_flags);
+	}
 }
 
 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
-- 
2.40.0