Messages in this thread Patch in this message | | | From | Liu Chao <> | Subject | [PATCH] genirq: Limit irq_calc_affinity_vectors to housekeeping CPUs | Date | Thu, 24 Dec 2020 12:23:13 +0800 |
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Replace the cpumask used in irq_calc_affinity_vectors from all possible CPUs to only housekeeping CPUs.
When we have isolated CPUs used by real-time tasks, IRQs will be move to housekeeping CPUs.
If there are too many IRQ vectors, moving the all to housekeeping CPUs may exceed per-CPU vector limits. For example, when I only have two housekeeping CPUs, there are dozens of IRQs on two CPUs, but actually one IRQ per housekeeping CPU is enough.
Signed-off-by: Liu Chao <liuchao173@huawei.com> --- kernel/irq/affinity.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c index 4d89ad4fae3b..3f22e3314e1b 100644 --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -8,6 +8,7 @@ #include <linux/slab.h> #include <linux/cpu.h> #include <linux/sort.h> +#include <linux/sched/isolation.h> static void irq_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk, unsigned int cpus_per_vec) @@ -506,7 +507,8 @@ unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec, set_vecs = maxvec - resv; } else { get_online_cpus(); - set_vecs = cpumask_weight(cpu_possible_mask); + set_vecs = cpumask_weight( + housekeeping_cpumask(HK_FLAG_MANAGED_IRQ)); put_online_cpus(); } -- 2.23.0
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