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| 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 | |
| parent | Linux 3.13-rc4 (diff) | |
| download | linux-d80512f87474f2dfd67ef931737659acce20fe69.tar.xz linux-d80512f87474f2dfd67ef931737659acce20fe69.zip | |
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')
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/smp.h | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/setup.c | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/smp.c | 25 |
4 files changed, 19 insertions, 10 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 1e1a03d2d19f..e9f312532526 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -135,7 +135,6 @@ config S390 select HAVE_SYSCALL_TRACEPOINTS select HAVE_UID16 if 32BIT select HAVE_VIRT_CPU_ACCOUNTING - select INIT_ALL_POSSIBLE select KTIME_SCALAR if 32BIT select MODULES_USE_ELF_RELA select OLD_SIGACTION diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h index ac9bed8e103f..160779394096 100644 --- a/arch/s390/include/asm/smp.h +++ b/arch/s390/include/asm/smp.h @@ -31,6 +31,7 @@ extern void smp_yield(void); extern void smp_stop_cpu(void); extern void smp_cpu_set_polarization(int cpu, int val); extern int smp_cpu_get_polarization(int cpu); +extern void smp_fill_possible_mask(void); #else /* CONFIG_SMP */ @@ -50,6 +51,7 @@ static inline int smp_vcpu_scheduled(int cpu) { return 1; } static inline void smp_yield_cpu(int cpu) { } static inline void smp_yield(void) { } static inline void smp_stop_cpu(void) { } +static inline void smp_fill_possible_mask(void) { } #endif /* CONFIG_SMP */ diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 4444875266ee..0f3d44ecbfc6 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -1023,6 +1023,7 @@ void __init setup_arch(char **cmdline_p) setup_vmcoreinfo(); setup_lowcore(); + smp_fill_possible_mask(); cpu_init(); s390_init_cpu_topology(); 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 */ |