From: Ashok Raj Date: Tue, 11 Apr 2006 05:53:07 +0000 (-0700) Subject: [PATCH] swsusp: don't require bigsmp X-Git-Tag: v2.6.17-rc2~256 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6cf272acd59e4e7a17b969adcdf413e15754bfe4;p=linux-2.6 [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 Cc: Pavel Machek Cc: "Rafael J. Wysocki" Cc: Nigel Cunningham Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/i386/kernel/mpparse.c b/arch/i386/kernel/mpparse.c index db120174aa..4f95c9cf79 100644 --- 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 + */ + if (num_processors > 8) { switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_INTEL: if (!APIC_XAPIC(ver)) {