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.

Link: https://lkml.kernel.org/r/20210923164741.1859522-4-bigeasy@linutronix.de
Link: https://lore.kernel.org/r/20210830172627.267989-4-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: Sebastian Andrzej Siewior

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;