linux/arch
Ashok Raj d3f4aaa3d7 [PATCH] x86: make CONFIG_HOTPLUG_CPU depend on !X86_PC
Make CONFIG_HOTPLUG_CPU depend on !X86_PC, so we need to turn on either
CONFIG_GENERICARCH, CONFIG_BIGSMP or any other subarch except X86_PC when
CONFIG_HOTPLUG_CPU=y

With 2.6.15+ kernels when CONFIG_HOTPLUG_CPU is turned on we switch to
bigsmp mode for sending IPI's and ioapic configurations that caused the
following error message.

>> More than 8 CPUs detected and CONFIG_X86_PC cannot handle it.
>> Use CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.

Originally bigsmp was added just to handle >8 cpus, but now with hotplug
cpu support we need to use bigsmp mode (why?  see below), that cause the
above error message even if there were less than 8 cpus in the system.

The message is bogus, but we are cannot use logical flat mode due to issues
with broadcast IPI can confuse a CPU just comming up.  We use flat physical
mode just like x86_64 case.  More details on why bigsmp now uses flat
physical mode (vs.  cluster mode) in following link.

http://marc.theaimsgroup.com/?l=linux-kernel&m=113261865814107&w=2

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:50 -08:00
..
alpha [PATCH] remove set_page_count() outside mm/ 2006-03-22 07:54:02 -08:00
arm [PATCH] s/;;/;/g 2006-03-24 07:33:24 -08:00
arm26 [PATCH] remove set_page_count() outside mm/ 2006-03-22 07:54:02 -08:00
cris [PATCH] set_page_dirty() return value fixes 2006-03-24 07:33:26 -08:00
frv [PATCH] s/;;/;/g 2006-03-24 07:33:24 -08:00
h8300 [PATCH] kill include/linux/platform.h, default_idle() cleanup 2006-03-24 07:33:21 -08:00
i386 [PATCH] x86: make CONFIG_HOTPLUG_CPU depend on !X86_PC 2006-03-25 08:22:50 -08:00
ia64 [PATCH] sys_alarm() unsigned signed conversion fixup 2006-03-25 08:22:48 -08:00
m32r [PATCH] more for_each_cpu() conversions 2006-03-23 07:38:17 -08:00
m68k [PATCH] kill include/linux/platform.h, default_idle() cleanup 2006-03-24 07:33:21 -08:00
m68knommu [PATCH] kill include/linux/platform.h, default_idle() cleanup 2006-03-24 07:33:21 -08:00
mips [PATCH] sys_alarm() unsigned signed conversion fixup 2006-03-25 08:22:48 -08:00
parisc [PATCH] kill include/linux/platform.h, default_idle() cleanup 2006-03-24 07:33:21 -08:00
powerpc [PATCH] more for_each_cpu() conversions 2006-03-23 07:38:17 -08:00
ppc [PATCH] s/;;/;/g 2006-03-24 07:33:24 -08:00
s390 [PATCH] kill include/linux/platform.h, default_idle() cleanup 2006-03-24 07:33:21 -08:00
sh [PATCH] kill include/linux/platform.h, default_idle() cleanup 2006-03-24 07:33:21 -08:00
sh64 [PATCH] more for_each_cpu() conversions 2006-03-23 07:38:17 -08:00
sparc [PATCH] more for_each_cpu() conversions 2006-03-23 07:38:17 -08:00
sparc64 [PATCH] s/;;/;/g 2006-03-24 07:33:24 -08:00
um [PATCH] x86: SMP alternatives 2006-03-23 07:38:04 -08:00
v850 [PATCH] kill include/linux/platform.h, default_idle() cleanup 2006-03-24 07:33:21 -08:00
x86_64 [PATCH] sys_alarm() unsigned signed conversion fixup 2006-03-25 08:22:48 -08:00
xtensa [PATCH] more for_each_cpu() conversions 2006-03-23 07:38:17 -08:00