1.1 --- a/linux-2.6-xen-sparse/drivers/xen/core/smpboot.c	Mon Jan 29 21:16:02 2007 +0000
     1.2 +++ b/linux-2.6-xen-sparse/drivers/xen/core/smpboot.c	Mon Jan 29 22:43:51 2007 +0000
     1.3 @@ -48,6 +48,7 @@ cpumask_t cpu_online_map;
     1.4  EXPORT_SYMBOL(cpu_online_map);
     1.5  cpumask_t cpu_possible_map;
     1.6  EXPORT_SYMBOL(cpu_possible_map);
     1.7 +static cpumask_t cpu_initialized_map;
     1.8  
     1.9  struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
    1.10  EXPORT_SYMBOL(cpu_data);
    1.11 @@ -278,6 +279,8 @@ void __init smp_prepare_cpus(unsigned in
    1.12  	if (xen_smp_intr_init(0))
    1.13  		BUG();
    1.14  
    1.15 +	cpu_initialized_map = cpumask_of_cpu(0);
    1.16 +
    1.17  	/* Restrict the possible_map according to max_cpus. */
    1.18  	while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
    1.19  		for (cpu = NR_CPUS-1; !cpu_isset(cpu, cpu_possible_map); cpu--)
    1.20 @@ -330,8 +333,6 @@ void __init smp_prepare_cpus(unsigned in
    1.21  #else
    1.22  		cpu_set(cpu, cpu_present_map);
    1.23  #endif
    1.24 -
    1.25 -		cpu_initialize_context(cpu);
    1.26  	}
    1.27  
    1.28  	init_xenbus_allowed_cpumask();
    1.29 @@ -418,6 +419,11 @@ int __devinit __cpu_up(unsigned int cpu)
    1.30  	if (rc)
    1.31  		return rc;
    1.32  
    1.33 +	if (!cpu_isset(cpu, cpu_initialized_map)) {
    1.34 +		cpu_set(cpu, cpu_initialized_map);
    1.35 +		cpu_initialize_context(cpu);
    1.36 +	}
    1.37 +
    1.38  	if (num_online_cpus() == 1)
    1.39  		alternatives_smp_switch(1);
    1.40