kcov: Allocate per-CPU memory on the relevant node.

During boot kcov allocates per-CPU memory which is used later if remote/
softirq processing is enabled.

Allocate the per-CPU memory on the CPU local node to avoid cross node
memory access.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20210830172627.267989-4-bigeasy@linutronix.de

kernel/kcov.c

@@ -1034,8 +1034,8 @@ static int __init kcov_init(void)
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
-		void *area = vmalloc(CONFIG_KCOV_IRQ_AREA_SIZE *
-				sizeof(unsigned long));
+		void *area = vmalloc_node(CONFIG_KCOV_IRQ_AREA_SIZE *
+				sizeof(unsigned long), cpu_to_node(cpu));
 		if (!area)
 			return -ENOMEM;
 		per_cpu_ptr(&kcov_percpu_data, cpu)->irq_area = area;