[PATCH] swsusp: don't require bigsmp

Switching to automatic bigsmp causes a misleading error message, that more
then 8 cpus are detected, and user needs to select either X86_GENERICARCH
or X86_BIGSMP to handle.

Reason is we switched to bigsmp to avoid IP race when new cpu is comming
up.  [bigsmp is nothing but using physical flat mode that can work for 1 ..
 255 cpus] [default is X86_PC, that uses logical flat mode up to 8 CPUs
max] Current x86_64 code uses bigsmp as default when hotplug is enabled.

It would be preferable to make bigsmp as default, and work the dependencies
of other related code like SMP_SUSPEND, and some related to memory hotplug
code for i386.

Current logical flat mode doesnt use shortcuts that cause the race by using
the send_IPI_mask() instead of shortcuts when HOTPLUG_CPU is enabled.

In the meantime this patch is the path of lease resistance.

We will switch to bigsmp default sometime soon, when we get to work it again.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Nigel Cunningham <nigel@suspend2.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/mpparse.c b/arch/i386/kernel/mpparse.c
index db120174aa7e3c1a3af3537c30012d3b4f735fe1..4f95c9cf7957993b783c52d2665866cd991a7fe6 100644 (file)
--- a/arch/i386/kernel/mpparse.c
+++ b/arch/i386/kernel/mpparse.c
@@ -38,12 +38,6 @@
 int smp_found_config;
 unsigned int __initdata maxcpus = NR_CPUS;
 
-#ifdef CONFIG_HOTPLUG_CPU
-#define CPU_HOTPLUG_ENABLED    (1)
-#else
-#define CPU_HOTPLUG_ENABLED    (0)
-#endif
-
 /*
  * Various Linux-internal data structures created from the
  * MP-table.
@@ -204,7 +198,14 @@ static void __devinit MP_processor_info (struct mpc_config_processor *m)
        cpu_set(num_processors, cpu_possible_map);
        num_processors++;
 
-       if (CPU_HOTPLUG_ENABLED || (num_processors > 8)) {
+       /*
+        * Would be preferable to switch to bigsmp when CONFIG_HOTPLUG_CPU=y
+        * but we need to work other dependencies like SMP_SUSPEND etc
+        * before this can be done without some confusion.
+        * if (CPU_HOTPLUG_ENABLED || num_processors > 8)
+        *       - Ashok Raj <ashok.raj@intel.com>
+        */
+       if (num_processors > 8) {
                switch (boot_cpu_data.x86_vendor) {
                case X86_VENDOR_INTEL:
                        if (!APIC_XAPIC(ver)) {