diff options
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 66 |
1 files changed, 40 insertions, 26 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9d921b78b145..a528c14d45a5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -949,52 +949,66 @@ config MAXSMP Enable maximum number of CPUS and NUMA Nodes for this architecture. If unsure, say N. -config RANGE_END_CPUS +# +# The maximum number of CPUs supported: +# +# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, +# and which can be configured interactively in the +# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. +# +# The ranges are different on 32-bit and 64-bit kernels, depending on +# hardware capabilities and scalability features of the kernel. +# +# ( If MAXSMP is enabled we just use the highest possible value and disable +# interactive configuration. ) +# + +config NR_CPUS_RANGE_BEGIN int - depends on X86_32 - default 8 if SMP && !X86_BIGSMP - default 64 if SMP && X86_BIGSMP - default 1 if !SMP + default NR_CPUS_RANGE_END if MAXSMP + default 1 if !SMP + default 2 -config RANGE_END_CPUS +config NR_CPUS_RANGE_END int - depends on X86_64 - default 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK - default 8192 if SMP && (MAXSMP || CPUMASK_OFFSTACK) - default 1 if !SMP + depends on X86_32 + default 64 if SMP && X86_BIGSMP + default 8 if SMP && !X86_BIGSMP + default 1 if !SMP -config RANGE_BEGIN_CPUS +config NR_CPUS_RANGE_END int - default 1 if !SMP - default RANGE_END_CPUS if MAXSMP - default 2 + depends on X86_64 + default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) + default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) + default 1 if !SMP -config DEF_CONFIG_CPUS +config NR_CPUS_DEFAULT int depends on X86_32 - default 1 if !SMP - default 32 if X86_BIGSMP - default 8 if SMP + default 32 if X86_BIGSMP + default 8 if SMP + default 1 if !SMP -config DEF_CONFIG_CPUS +config NR_CPUS_DEFAULT int depends on X86_64 - default 1 if !SMP - default 8192 if MAXSMP - default 64 if SMP + default 8192 if MAXSMP + default 64 if SMP + default 1 if !SMP config NR_CPUS int "Maximum number of CPUs" if SMP && !MAXSMP - range RANGE_BEGIN_CPUS RANGE_END_CPUS - default DEF_CONFIG_CPUS + range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END + default NR_CPUS_DEFAULT ---help--- This allows you to specify the maximum number of CPUs which this kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum supported value is 8192, otherwise the maximum value is 512. The minimum value which makes sense is 2. - This is purely to save memory - each supported CPU adds - approximately eight kilobytes to the kernel image. + This is purely to save memory: each supported CPU adds about 8KB + to the kernel image. config SCHED_SMT bool "SMT (Hyperthreading) scheduler support" |