add per_cpu_dyn_array support

allow dyn-array in per_cpu area, allocated dynamically.

usage:

|  /* in .h */
| struct kernel_stat {
|        struct cpu_usage_stat   cpustat;
|        unsigned int *irqs;
| };
|
|  /* in .c */
| DEFINE_PER_CPU(struct kernel_stat, kstat);
|
| DEFINE_PER_CPU_DYN_ARRAY_ADDR(per_cpu__kstat_irqs, per_cpu__kstat.irqs, sizeof(unsigned int), nr_irqs, sizeof(unsigned long), NULL);

after setup_percpu()/per_cpu_alloc_dyn_array(), the dyn_array in
per_cpu area is ready to use.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 0e67f72d9316..13ba7a83808d 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -140,7 +140,7 @@ static void __init setup_cpu_pda_map(void)
  */
 void __init setup_per_cpu_areas(void)
 {
-        ssize_t size = PERCPU_ENOUGH_ROOM;
+        ssize_t size, old_size;
         char *ptr;
         int cpu;
 
@@ -148,7 +148,8 @@ void __init setup_per_cpu_areas(void)
         setup_cpu_pda_map();
 
         /* Copy section for each CPU (we discard the original) */
-        size = PERCPU_ENOUGH_ROOM;
+        old_size = PERCPU_ENOUGH_ROOM;
+        size = old_size + per_cpu_dyn_array_size();
         printk(KERN_INFO "PERCPU: Allocating %zd bytes of per cpu data\n",
                           size);
 
@@ -176,6 +177,8 @@ void __init setup_per_cpu_areas(void)
                 per_cpu_offset(cpu) = ptr - __per_cpu_start;
                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 
+                per_cpu_alloc_dyn_array(cpu, ptr + old_size);
+
         }
 
         printk(KERN_DEBUG "NR_CPUS: %d, nr_cpu_ids: %d, nr_node_ids %d\n",