Commit 6cf272ac authored Apr 10, 2006 by Ashok Raj Committed by Linus Torvalds Apr 11, 2006

[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>

parent 3016b421

arch/i386/kernel/mpparse.c

+8 −7

Original line number	Diff line number	Diff line
		@@ -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)) {