[PATCH] x86: sutomatically enable bigsmp when we have more than 8 CPUs

i386 generic subarchitecture requires explicit dmi strings or command line
to enable bigsmp mode.  The patch below removes that restriction, and uses
bigsmp as soon as it finds more than 8 logical CPUs, Intel processors and
xAPIC support.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c
index 9adbf710ec8d..294bcca985ab 100644
--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -1585,8 +1585,14 @@ void __init setup_arch(char **cmdline_p)
          */
         acpi_boot_table_init();
         acpi_boot_init();
-#endif
 
+#if defined(CONFIG_SMP) && defined(CONFIG_X86_PC)
+        if (def_to_bigsmp)
+                printk(KERN_WARNING "More than 8 CPUs detected and "
+                        "CONFIG_X86_PC cannot handle it.\nUse "
+                        "CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n");
+#endif
+#endif
 #ifdef CONFIG_X86_LOCAL_APIC
         if (smp_found_config)
                 get_smp_config();