From: Ashok Raj Date: Fri, 28 Apr 2006 01:39:30 +0000 (-0700) Subject: [PATCH] enable X86_PC for HOTPLUG_CPU X-Git-Tag: v2.6.17-rc4~128 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35076bdfa171cd83d89fcb96568e786f0da91d9f;p=linux-2.6 [PATCH] enable X86_PC for HOTPLUG_CPU CPU_HOTPLUG has race conditions when we use broadcast mode IPI. - First we introduced no_broadcast option (see include/asm-i386/mach-default/mach_ipi.h) - x86_64 solved it by using physical flat mode (same as bigsmp on i386) since this will not use broadcast shortcuts for IPI. - We switched to use bigsmp on i386 so that we can have same handling as x86_64, but apparently this caused an error message, if kernel was compiled without X86_GENERICARCH, X86_BIGSMP. The message "You have >8 CPUS..." which was bogus and misleading, and only indicated one of the above ARCH wasnt selected. So we do not switch to automatic bigsmp for HOTPLUG_CPU support in i386 until the other related config dependencies for SMP_SUSPEND etc can be done right. Signed-off-by: Ashok Raj Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig index 18ec9fe6de..366b401c1f 100644 --- a/arch/i386/Kconfig +++ b/arch/i386/Kconfig @@ -756,7 +756,7 @@ config PHYSICAL_START config HOTPLUG_CPU bool "Support for hot-pluggable CPUs (EXPERIMENTAL)" - depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER && !X86_PC + depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER ---help--- Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu.