x86, fpu: lazy allocation of FPU area - v5
[linux-2.6.git] / arch / x86 / kernel / process.c
index ead24ef..0e613e7 100644 (file)
@@ -5,24 +5,34 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 
-static struct kmem_cache *task_xstate_cachep;
+struct kmem_cache *task_xstate_cachep;
 
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
        *dst = *src;
-       dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL);
-       if (!dst->thread.xstate)
-               return -ENOMEM;
-       WARN_ON((unsigned long)dst->thread.xstate & 15);
-       memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
+       if (src->thread.xstate) {
+               dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
+                                                     GFP_KERNEL);
+               if (!dst->thread.xstate)
+                       return -ENOMEM;
+               WARN_ON((unsigned long)dst->thread.xstate & 15);
+               memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
+       }
        return 0;
 }
 
-void free_thread_info(struct thread_info *ti)
+void free_thread_xstate(struct task_struct *tsk)
 {
-       kmem_cache_free(task_xstate_cachep, ti->task->thread.xstate);
-       ti->task->thread.xstate = NULL;
+       if (tsk->thread.xstate) {
+               kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
+               tsk->thread.xstate = NULL;
+       }
+}
+
 
+void free_thread_info(struct thread_info *ti)
+{
+       free_thread_xstate(ti->task);
        free_pages((unsigned long)(ti), get_order(THREAD_SIZE));
 }