Introduce possible_cpus command line option. Hard sets the number of bits set
in cpu_possible_map. Unlike the additional_cpus parameter this one guarantees
that num_possible_cpus() will stay constant even if the system gets rebooted
and a different number of cpus are present at startup.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
parameter "additional_cpus=x" to represent those cpus in the cpu_possible_map.
parameter "additional_cpus=x" to represent those cpus in the cpu_possible_map.
+possible_cpus=n [s390 only] use this to set hotpluggable cpus.
+ This option sets possible_cpus bits in
+ cpu_possible_map. Thus keeping the numbers of bits set
+ constant even if the machine gets rebooted.
+ This option overrides additional_cpus.
+
CPU maps and such
-----------------
[More on cpumaps and primitive to manipulate, please check
CPU maps and such
-----------------
[More on cpumaps and primitive to manipulate, please check
}
static unsigned int __initdata additional_cpus;
}
static unsigned int __initdata additional_cpus;
+static unsigned int __initdata possible_cpus;
void __init smp_setup_cpu_possible_map(void)
{
unsigned int pcpus, cpu;
void __init smp_setup_cpu_possible_map(void)
{
unsigned int pcpus, cpu;
- pcpus = smp_count_cpus() + additional_cpus;
+ pcpus = min(smp_count_cpus() + additional_cpus, (unsigned int) NR_CPUS);
- if (pcpus > NR_CPUS)
- pcpus = NR_CPUS;
+ if (possible_cpus)
+ pcpus = min(possible_cpus, (unsigned int) NR_CPUS);
for (cpu = 0; cpu < pcpus; cpu++)
cpu_set(cpu, cpu_possible_map);
for (cpu = 0; cpu < pcpus; cpu++)
cpu_set(cpu, cpu_possible_map);
}
early_param("additional_cpus", setup_additional_cpus);
}
early_param("additional_cpus", setup_additional_cpus);
+static int __init setup_possible_cpus(char *s)
+{
+ possible_cpus = simple_strtoul(s, NULL, 0);
+ return 0;
+}
+early_param("possible_cpus", setup_possible_cpus);
+
int
__cpu_disable(void)
{
int
__cpu_disable(void)
{