Commit 4e36eb46 authored Jun 22, 2017 by Pavankumar Kondeti Committed by Satya Durga Srinivasu Prabhala Jan 02, 2019

genriq: pick only one CPU while overriding the affinity during migration

With commit bfc60d474137 ("genirq: Use irq_set_affinity_locked to change
irq affinity"), affinity listeners receive the notification when the irq
affinity is changed during migration. If there is no online and
un-isolated CPU available from the user specified affinity, the affinity
is overridden with all online and un-isolated CPUs. The same cpumask is
notified to PM QOS affinity listener which applies PM_QOS_CPU_DMA_LATENCY
vote to all those CPUs. As the low level irqchip driver sets affinity to
only one CPU, do the same while overriding the affinity during migration.

Change-Id: I0bcb75dd356658da100fbeeefd33ef8b121f4d6d
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>

parent eeb3c956

kernel/irq/cpuhotplug.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -129,6 +129,17 @@ static bool migrate_one_irq(struct irq_desc *desc)
		cpu_isolated_mask);
		if (cpumask_empty(affinity))
		affinity = cpu_online_mask;
		/*
		* We are overriding the affinity with all online and
		* un-isolated cpus. irq_set_affinity_locked() call
		* below notify this mask to PM QOS affinity listener.
		* That results in applying the CPU_DMA_LATENCY QOS
		* to all the CPUs specified in the mask. But the low
		* level irqchip driver sets the affinity of an irq
		* to only one CPU. So pick only one CPU from the
		* prepared mask while overriding the user affinity.
		*/
		affinity = cpumask_of(cpumask_any(affinity));
		brokeaff = true;
		}
		/*