From: Ma Jun <majun...@huawei.com> When the CPU of a non-balanced irq bounded is off line, the irq will be migrated to other CPUs, usually the first cpu on-line.
We can suppose the situation if a system has more than one non-balanced irq. At extreme case, these irqs will be migrated to the same CPU and will cause the CPU run with high irq pressure, even make the system die. So, I think maybe we need to change the non-balanced irq to a irq can be balanced to avoid the problem descried above. Maybe this is not a good solution for this problem, please offer me some suggestion if you have a better one. Signed-off-by: Ma Jun <majun...@huawei.com> --- kernel/irq/cpuhotplug.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index 011f8c4..80d54a5 100644 --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -30,6 +30,8 @@ static bool migrate_one_irq(struct irq_desc *desc) return false; if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { + if (irq_settings_has_no_balance_set(desc)) + irqd_clear(d, IRQD_NO_BALANCING); affinity = cpu_online_mask; ret = true; } -- 1.7.1