From: Jens Axboe <jaxboe@fusionio.com>
Date: Fri, 8 Oct 2010 11:37:49 +0000 (+0200)
Subject: Add and use slab init_once functionality
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=146229b60c943d8b9e48ec96969103fe82ab4244;p=binject.git

Add and use slab init_once functionality

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
---

diff --git a/kcompat.h b/kcompat.h
index 366a4f2..8828652 100644
--- a/kcompat.h
+++ b/kcompat.h
@@ -50,13 +50,14 @@ static inline ktime_t ktime_get(void)
 }
 #endif
 
-static inline struct kmem_cache *binject_create_slab(const char *name,
-						     size_t obj_size)
+static inline struct kmem_cache *
+binject_create_slab(const char *name, size_t obj_size, unsigned long flags,
+		    void (*init_once)(void *))
 {
 #if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 26)
-	return kmem_cache_create(name, obj_size, 0, 0, NULL);
+	return kmem_cache_create(name, obj_size, 0, flags, NULL);
 #else
-	return kmem_cache_create(name, obj_size, 0, 0, NULL, NULL);
+	return kmem_cache_create(name, obj_size, 0, flags, init_once, NULL);
 #endif
 }
 
diff --git a/main.c b/main.c
index 676fd1e..91f81a2 100644
--- a/main.c
+++ b/main.c
@@ -160,8 +160,6 @@ static struct b_cmd *get_free_command(struct b_dev *bd)
 
 	bc = kmem_cache_alloc(b_slab, GFP_KERNEL);
 	if (bc) {
-		memset(bc, 0, sizeof(*bc));
-		INIT_LIST_HEAD(&bc->list);
 		bc->bd = bd;
 		return bc;
 	}
@@ -177,7 +175,7 @@ static struct b_cmd *get_completed_command(struct b_dev *bd)
 	if (!list_empty(&bd->done_list)) {
 		bc = list_entry(bd->done_list.next, struct b_cmd, list);
 		bd->done_cmds--;
-		list_del(&bc->list);
+		list_del_init(&bc->list);
 	}
 	spin_unlock_irq(&bd->lock);
 	return bc;
@@ -412,6 +410,7 @@ static int b_dev_add_command(struct b_dev *bd, struct b_cmd *bc)
 
 static void b_dev_free_command(struct b_dev *bd, struct b_cmd *bc)
 {
+	BUG_ON(!list_empty(&bc->list));
 	kmem_cache_free(b_slab, bc);
 }
 
@@ -708,11 +707,19 @@ static void __exit b_exit(void)
 	misc_deregister(&b_misc_dev);
 }
 
+static void b_cmd_init_once(void *data)
+{
+	struct b_cmd *bc = data;
+
+	INIT_LIST_HEAD(&bc->list);
+}
+
 static int __init b_init(void)
 {
 	int ret;
 
-	b_slab = binject_create_slab("binject", sizeof(struct b_cmd));
+	b_slab = binject_create_slab("binject", sizeof(struct b_cmd),
+					SLAB_HWCACHE_ALIGN, b_cmd_init_once);
 	if (!b_slab) {
 		printk(KERN_ERR "binject: failed to create cmd slab\n");
 		return -ENOMEM;