[PATCH] allow thread_info to be allocated as part of task_struct

This re-organizes the thread info allocations a bit, so that
architectures like ia64 that want to allocate the thread_info structure
as part of the task structure allocation can do so.

The bulk of the patch is adding the "tsk" information to the thread
info allocator (ignored by all non-ia64 architectures), and switching
the order of the allocators to make this all possible.

1 files changed, 18 insertions, 12 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 23c6d34f800f..7fe73cf41ac5 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -38,8 +38,6 @@
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
-static kmem_cache_t *task_struct_cachep;
-
 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
 extern void exit_semundo(struct task_struct *tsk);
 
@@ -74,7 +72,13 @@ int nr_processes(void)
 	return total;
 }
 
-static void free_task_struct(struct task_struct *tsk)
+#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
+# define alloc_task_struct()	kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
+# define free_task_struct(tsk)	kmem_cache_free(task_struct_cachep, (tsk))
+static kmem_cache_t *task_struct_cachep;
+#endif
+
+static void free_task(struct task_struct *tsk)
 {
 	/*
 	 * The task cache is effectively disabled right now.
@@ -84,14 +88,14 @@ static void free_task_struct(struct task_struct *tsk)
 	 */
 	if (tsk != current) {
 		free_thread_info(tsk->thread_info);
-		kmem_cache_free(task_struct_cachep,tsk);
+		free_task_struct(tsk);
 	} else {
 		int cpu = get_cpu();
 
 		tsk = task_cache[cpu];
 		if (tsk) {
 			free_thread_info(tsk->thread_info);
-			kmem_cache_free(task_struct_cachep,tsk);
+			free_task_struct(tsk);
 		}
 		task_cache[cpu] = current;
 		put_cpu();
@@ -106,7 +110,7 @@ void __put_task_struct(struct task_struct *tsk)
 
 	security_task_free(tsk);
 	free_uid(tsk->user);
-	free_task_struct(tsk);
+	free_task(tsk);
 }
 
 void add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)
@@ -186,6 +190,7 @@ int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync)
 
 void __init fork_init(unsigned long mempages)
 {
+#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
 	/* create a slab on which task_structs can be allocated */
 	task_struct_cachep =
 		kmem_cache_create("task_struct",
@@ -193,6 +198,7 @@ void __init fork_init(unsigned long mempages)
 				  SLAB_MUST_HWCACHE_ALIGN, NULL, NULL);
 	if (!task_struct_cachep)
 		panic("fork_init(): cannot create task_struct SLAB cache");
+#endif
 
 	/*
 	 * The default maximum number of threads is set to a safe
@@ -222,13 +228,13 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 	task_cache[cpu] = NULL;
 	put_cpu();
 	if (!tsk) {
-		ti = alloc_thread_info();
-		if (!ti)
+		tsk = alloc_task_struct();
+		if (!tsk)
 			return NULL;
 
-		tsk = kmem_cache_alloc(task_struct_cachep, GFP_KERNEL);
-		if (!tsk) {
-			free_thread_info(ti);
+		ti = alloc_thread_info(tsk);
+		if (!ti) {
+			free_task_struct(tsk);
 			return NULL;
 		}
 	} else
@@ -1041,7 +1047,7 @@ bad_fork_cleanup_count:
 	atomic_dec(&p->user->processes);
 	free_uid(p->user);
 bad_fork_free:
-	free_task_struct(p);
+	free_task(p);
 	goto fork_out;
 }