From d80512f87474f2dfd67ef931737659acce20fe69 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 16 Dec 2013 14:31:26 +0100 Subject: s390/smp: improve setup of possible cpu mask Since under z/VM we cannot have more than 64 cpus, make sure the cpu_possible_mask does not contain more bits. This avoids wasting memory for dynamic per-cpu allocations if CONFIG_NR_CPUS is larger than 64. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/smp.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'arch/s390/kernel/smp.c') diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index dc4a53465060..958704798f4a 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -721,18 +721,14 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) return 0; } -static int __init setup_possible_cpus(char *s) -{ - int max, cpu; +static unsigned int setup_possible_cpus __initdata; - if (kstrtoint(s, 0, &max) < 0) - return 0; - init_cpu_possible(cpumask_of(0)); - for (cpu = 1; cpu < max && cpu < nr_cpu_ids; cpu++) - set_cpu_possible(cpu, true); +static int __init _setup_possible_cpus(char *s) +{ + get_option(&s, &setup_possible_cpus); return 0; } -early_param("possible_cpus", setup_possible_cpus); +early_param("possible_cpus", _setup_possible_cpus); #ifdef CONFIG_HOTPLUG_CPU @@ -775,6 +771,17 @@ void __noreturn cpu_die(void) #endif /* CONFIG_HOTPLUG_CPU */ +void __init smp_fill_possible_mask(void) +{ + unsigned int possible, cpu; + + possible = setup_possible_cpus; + if (!possible) + possible = MACHINE_IS_VM ? 64 : nr_cpu_ids; + for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) + set_cpu_possible(cpu, true); +} + void __init smp_prepare_cpus(unsigned int max_cpus) { /* request the 0x1201 emergency signal external interrupt */ -- cgit v1.2.3