Rafael J. Wysocki wrote: > We use the CPU hotplug code for disabling/enabling nonboot CPUs. > > You need to enable it to be able to suspend (BTW, it's also necesary for > the suspend to RAM). I now noticed that this is documented in the help text of i386's Kconfig. But it is not mentioned in the help text of x86_64's Kconfig. Also, I think that should already be shown in the prompt, not just in the help text. From: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx> Subject: i386, x86-64: show that CONFIG_HOTPLUG_CPU is required for suspend on SMP Point out the non-obvious. Signed-off-by: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx> --- arch/i386/Kconfig | 2 +- arch/x86_64/Kconfig | 7 +++++-- 2 files changed, 6 insertions(+), 3 deletions(-) Index: linux/arch/i386/Kconfig =================================================================== --- linux.orig/arch/i386/Kconfig +++ linux/arch/i386/Kconfig @@ -891,7 +891,7 @@ config PHYSICAL_ALIGN Don't change this unless you know what you are doing. config HOTPLUG_CPU - bool "Support for hot-pluggable CPUs (EXPERIMENTAL)" + bool "Support for suspend on SMP hot-pluggable CPUs (EXPERIMENTAL)" depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER ---help--- Say Y here to experiment with turning CPUs off and on, and to Index: linux/arch/x86_64/Kconfig =================================================================== --- linux.orig/arch/x86_64/Kconfig +++ linux/arch/x86_64/Kconfig @@ -428,12 +428,15 @@ config NR_CPUS memory in the static kernel configuration. config HOTPLUG_CPU - bool "Support for hot-pluggable CPUs (EXPERIMENTAL)" + bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)" depends on SMP && HOTPLUG && EXPERIMENTAL help Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu/cpu#. - Say N if you want to disable CPU hotplug. + This is also required for suspend on SMP systems. + + Say N if you want to disable CPU hotplug and don't need to + suspend. config ARCH_ENABLE_MEMORY_HOTPLUG def_bool y -- Stefan Richter -=====-=-=== -=-= =-=-- http://arcgraph.de/sr/ _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
