Commit 35076bdf authored by Ashok Raj's avatar Ashok Raj Committed by Linus Torvalds

[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: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7f5910ec
...@@ -756,7 +756,7 @@ config PHYSICAL_START ...@@ -756,7 +756,7 @@ config PHYSICAL_START
config HOTPLUG_CPU config HOTPLUG_CPU
bool "Support for hot-pluggable CPUs (EXPERIMENTAL)" bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER && !X86_PC depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
---help--- ---help---
Say Y here to experiment with turning CPUs off and on. CPUs Say Y here to experiment with turning CPUs off and on. CPUs
can be controlled through /sys/devices/system/cpu. can be controlled through /sys/devices/system/cpu.
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment