idr: create idr_layer_cache at boot time

Avoid a possible kmem_cache_create() failure by creating idr_layer_cache
unconditionary at boot time rather than creating it on-demand when idr_init()
is called the first time.

This change also enables us to eliminate the check every time idr_init() is
called.

[akpm@linux-foundation.org: rename init_id_cache() to idr_init_cache()]
[akpm@linux-foundation.org: fix alpha build]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/lib/idr.c b/lib/idr.c
index afbb0b1023d4..8368c81fcb7d 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -585,12 +585,11 @@ static void idr_cache_ctor(struct kmem_cache *idr_layer_cache, void *idr_layer)
         memset(idr_layer, 0, sizeof(struct idr_layer));
 }
 
-static  int init_id_cache(void)
+void __init idr_init_cache(void)
 {
-        if (!idr_layer_cache)
-                idr_layer_cache = kmem_cache_create("idr_layer_cache",
-                        sizeof(struct idr_layer), 0, 0, idr_cache_ctor);
-        return 0;
+        idr_layer_cache = kmem_cache_create("idr_layer_cache",
+                                sizeof(struct idr_layer), 0, SLAB_PANIC,
+                                idr_cache_ctor);
 }
 
 /**
@@ -602,7 +601,6 @@ static  int init_id_cache(void)
  */
 void idr_init(struct idr *idp)
 {
-        init_id_cache();
         memset(idp, 0, sizeof(struct idr));
         spin_lock_init(&idp->lock);
 }