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Diffstat (limited to 'arch/x86/Kconfig')
-rw-r--r-- | arch/x86/Kconfig | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 46c3bff3ced..036e89ab470 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1698,6 +1698,35 @@ config HOTPLUG_CPU automatically on SMP systems. ) Say N if you want to disable CPU hotplug. +config BOOTPARAM_HOTPLUG_CPU0 + bool "Set default setting of cpu0_hotpluggable" + default n + depends on HOTPLUG_CPU && EXPERIMENTAL + ---help--- + Set whether default state of cpu0_hotpluggable is on or off. + + Say Y here to enable CPU0 hotplug by default. If this switch + is turned on, there is no need to give cpu0_hotplug kernel + parameter and the CPU0 hotplug feature is enabled by default. + + Please note: there are two known CPU0 dependencies if you want + to enable the CPU0 hotplug feature either by this switch or by + cpu0_hotplug kernel parameter. + + First, resume from hibernate or suspend always starts from CPU0. + So hibernate and suspend are prevented if CPU0 is offline. + + Second dependency is PIC interrupts always go to CPU0. CPU0 can not + offline if any interrupt can not migrate out of CPU0. There may + be other CPU0 dependencies. + + Please make sure the dependencies are under your control before + you enable this feature. + + Say N if you don't want to enable CPU0 hotplug feature by default. + You still can enable the CPU0 hotplug feature at boot by kernel + parameter cpu0_hotplug. + config COMPAT_VDSO def_bool y prompt "Compat VDSO support" |