KMEM_CACHE(): simplify slab cache creation

This patch provides a new macro

KMEM_CACHE(<struct>, <flags>)

to simplify slab creation. KMEM_CACHE creates a slab with the name of the
struct, with the size of the struct and with the alignment of the struct.
Additional slab flags may be specified if necessary.

Example

struct test_slab {
	int a,b,c;
	struct list_head;
} __cacheline_aligned_in_smp;

test_slab_cache = KMEM_CACHE(test_slab, SLAB_PANIC)

will create a new slab named "test_slab" of the size sizeof(struct
test_slab) and aligned to the alignment of test slab.  If it fails then we
panic.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 files changed, 23 insertions, 32 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 64df3fa303b..baef5fc7cff 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2090,13 +2090,11 @@ static void cfq_slab_kill(void)
 
 static int __init cfq_slab_setup(void)
 {
-	cfq_pool = kmem_cache_create("cfq_pool", sizeof(struct cfq_queue), 0, 0,
-					NULL, NULL);
+	cfq_pool = KMEM_CACHE(cfq_queue, 0);
 	if (!cfq_pool)
 		goto fail;
 
-	cfq_ioc_pool = kmem_cache_create("cfq_ioc_pool",
-			sizeof(struct cfq_io_context), 0, 0, NULL, NULL);
+	cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0);
 	if (!cfq_ioc_pool)
 		goto fail;
 
diff --git a/fs/aio.c b/fs/aio.c
index e4598d6d49d..b97ab8028b6 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -68,10 +68,8 @@ static void aio_queue_work(struct kioctx *);
  */
 static int __init aio_setup(void)
 {
-	kiocb_cachep = kmem_cache_create("kiocb", sizeof(struct kiocb),
-				0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
-	kioctx_cachep = kmem_cache_create("kioctx", sizeof(struct kioctx),
-				0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
+	kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
+	kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
 
 	aio_wq = create_workqueue("aio");
 
diff --git a/fs/bio.c b/fs/bio.c
index 693940da409..093345f0012 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1193,8 +1193,7 @@ static void __init biovec_init_slabs(void)
 
 static int __init init_bio(void)
 {
-	bio_slab = kmem_cache_create("bio", sizeof(struct bio), 0,
-				SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
+	bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
 
 	biovec_init_slabs();
 
diff --git a/fs/dcache.c b/fs/dcache.c
index d68631f18df..d1bf5d8aeb5 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2052,12 +2052,8 @@ static void __init dcache_init(unsigned long mempages)
 	 * but it is probably not worth it because of the cache nature
 	 * of the dcache. 
 	 */
-	dentry_cache = kmem_cache_create("dentry_cache",
-					 sizeof(struct dentry),
-					 0,
-					 (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
-					 SLAB_MEM_SPREAD),
-					 NULL, NULL);
+	dentry_cache = KMEM_CACHE(dentry,
+		SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD);
 	
 	set_shrinker(DEFAULT_SEEKS, shrink_dcache_memory);
 
diff --git a/include/linux/slab.h b/include/linux/slab.h
index a9befa50d3e..e14b4c338b8 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -57,6 +57,18 @@ unsigned int kmem_cache_size(struct kmem_cache *);
 const char *kmem_cache_name(struct kmem_cache *);
 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
 
+/*
+ * Please use this macro to create slab caches. Simply specify the
+ * name of the structure and maybe some flags that are listed above.
+ *
+ * The alignment of the struct determines object alignment. If you
+ * f.e. add ____cacheline_aligned_in_smp to the struct declaration
+ * then the objects will be properly aligned in SMP configurations.
+ */
+#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
+		sizeof(struct __struct), __alignof__(struct __struct),\
+		(__flags), NULL, NULL)
+
 #ifdef CONFIG_NUMA
 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 #else
diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index 766d5912b26..c0148ae992c 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -31,11 +31,7 @@ __setup("nodelayacct", delayacct_setup_disable);
 
 void delayacct_init(void)
 {
-	delayacct_cache = kmem_cache_create("delayacct_cache",
-					sizeof(struct task_delay_info),
-					0,
-					SLAB_PANIC,
-					NULL, NULL);
+	delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC);
 	delayacct_tsk_init(&init_task);
 }
 
diff --git a/kernel/pid.c b/kernel/pid.c
index 78f2aee90f5..9c80bc23d6b 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -412,7 +412,5 @@ void __init pidmap_init(void)
 	set_bit(0, init_pid_ns.pidmap[0].page);
 	atomic_dec(&init_pid_ns.pidmap[0].nr_free);
 
-	pid_cachep = kmem_cache_create("pid", sizeof(struct pid),
-					__alignof__(struct pid),
-					SLAB_PANIC, NULL, NULL);
+	pid_cachep = KMEM_CACHE(pid, SLAB_PANIC);
 }
diff --git a/kernel/signal.c b/kernel/signal.c
index 3670225ecbc..2b4087d545a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2636,9 +2636,5 @@ __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma)
 
 void __init signals_init(void)
 {
-	sigqueue_cachep =
-		kmem_cache_create("sigqueue",
-				  sizeof(struct sigqueue),
-				  __alignof__(struct sigqueue),
-				  SLAB_PANIC, NULL, NULL);
+	sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC);
 }
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index ad7d2392cb0..906cae77158 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -524,9 +524,7 @@ void __init taskstats_init_early(void)
 {
 	unsigned int i;
 
-	taskstats_cache = kmem_cache_create("taskstats_cache",
-						sizeof(struct taskstats),
-						0, SLAB_PANIC, NULL, NULL);
+	taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC);
 	for_each_possible_cpu(i) {
 		INIT_LIST_HEAD(&(per_cpu(listener_array, i).list));
 		init_rwsem(&(per_cpu(listener_array, i).sem));