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, 2 insertions, 0 deletions

diff --git a/init/main.c b/init/main.c
index c62c98f381f2..624266b524d4 100644
--- a/init/main.c
+++ b/init/main.c
@@ -58,6 +58,7 @@
 #include <linux/kthread.h>
 #include <linux/sched.h>
 #include <linux/signal.h>
+#include <linux/idr.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>
@@ -637,6 +638,7 @@ asmlinkage void __init start_kernel(void)
         enable_debug_pagealloc();
         cpu_hotplug_init();
         kmem_cache_init();
+        idr_init_cache();
         setup_per_cpu_pageset();
         numa_policy_init();
         if (late_time_init)