diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2013-12-16 14:31:26 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-12-18 17:35:18 +0100 |
| commit | d80512f87474f2dfd67ef931737659acce20fe69 (patch) | |
| tree | dac6a70fa90b58bdf396292e95dced35c3caccff /arch/s390/kernel/smp.c | |
| parent | 319e2e3f63c348a9b66db4667efa73178e18b17d (diff) | |
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/smp.c')
| -rw-r--r-- | arch/s390/kernel/smp.c | 25 |
1 files changed, 16 insertions, 9 deletions
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 */ |