fork時のaudit_alloc_context()でkmalloc()じゃなくてkmem_cache_alloc()を使うpatch。for 3.10-rc1

use_slab_cache.patch

diff --git a/include/linux/audit.h b/include/linux/audit.h
index b20b038..2eb4be2 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -94,6 +94,7 @@ extern void audit_log_session_info(struct audit_buffer *ab);
 #ifdef CONFIG_AUDITSYSCALL
 /* These are defined in auditsc.c */
 				/* Public API */
+extern int __init audit_cache_init(void);
 extern int  audit_alloc(struct task_struct *task);
 extern void __audit_free(struct task_struct *task);
 extern void __audit_syscall_entry(int arch,
@@ -285,6 +286,10 @@ static inline void audit_mmap_fd(int fd, int flags)
 extern int audit_n_rules;
 extern int audit_signals;
 #else /* CONFIG_AUDITSYSCALL */
+static inline int __init audit_cache_init(void)
+{
+	return 0;
+}
 static inline int audit_alloc(struct task_struct *task)
 {
 	return 0;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 3c8a601..bc6c2e3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -132,6 +132,8 @@ struct audit_tree_refs {
 	struct audit_chunk *c[31];
 };
 
+static struct kmem_cache *audit_cachep;
+
 static inline int open_arg(int flags, int mask)
 {
 	int n = ACC_MODE(flags);
@@ -914,9 +916,10 @@ static inline struct audit_context *audit_alloc_context(enum audit_state state)
 {
 	struct audit_context *context;
 
-	context = kzalloc(sizeof(*context), GFP_KERNEL);
+	context = kmem_cache_alloc(audit_cachep, GFP_KERNEL);
 	if (!context)
 		return NULL;
+	memset(context, 0, sizeof(*context));
 	context->state = state;
 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
 	INIT_LIST_HEAD(&context->killed_trees);
@@ -966,7 +969,7 @@ static inline void audit_free_context(struct audit_context *context)
 	audit_free_aux(context);
 	kfree(context->filterkey);
 	kfree(context->sockaddr);
-	kfree(context);
+	kmem_cache_free(audit_cachep, context);
 }
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
@@ -2416,3 +2419,11 @@ struct list_head *audit_killed_trees(void)
 		return NULL;
 	return &ctx->killed_trees;
 }
+
+int __init audit_cache_init(void)
+{
+	printk(KERN_INFO"use slab cache instead of kmalloc in audit_alloc_context()\n");
+	audit_cachep = KMEM_CACHE(audit_context, SLAB_PANIC);
+	return 0;
+}
+
diff --git a/kernel/fork.c b/kernel/fork.c
index 987b28a..2b8e2e1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1726,6 +1726,7 @@ void __init proc_caches_init(void)
 	vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC);
 	mmap_init();
 	nsproxy_cache_init();
+	audit_cache_init();
 }
 
 /*