From: Dietmar Eggemann dietmar.eggemann@arm.com
This patch limits the default affinity mask for all irqs to the cluster of the little cpus.
This patch has the positive side effect that an irq thread which has its IRQTF_RUNTHREAD set inside irq_thread() -> irq_wait_for_interrupt() will not overwrite its struct task_struct->cpus_allowed with a full cpu mask of desc->irq_data.affinity in irq_thread_check_affinity() essentially reverting patch "HMP: experimental: Force all rt tasks to start on little domain." for this irq thread.
Signed-off-by: Dietmar Eggemann dietmar.eggemann@arm.com Signed-off-by: Jon Medhurst tixy@linaro.org --- kernel/irq/irqdesc.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 473b2b6..20ecfb0 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -36,12 +36,20 @@ static int __init irq_affinity_setup(char *str) } __setup("irqaffinity=", irq_affinity_setup);
+extern struct cpumask hmp_slow_cpu_mask; + static void __init init_irq_default_affinity(void) { #ifdef CONFIG_CPUMASK_OFFSTACK if (!irq_default_affinity) zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); #endif +#ifdef CONFIG_SCHED_HMP + if (!cpumask_empty(&hmp_slow_cpu_mask)) { + cpumask_copy(irq_default_affinity, &hmp_slow_cpu_mask); + return; + } +#endif if (cpumask_empty(irq_default_affinity)) cpumask_setall(irq_default_affinity); }