From b9049e234401e1fad8459d69a952b174d76c399d Mon Sep 17 00:00:00 2001 From: Yasunori Goto Date: Sun, 21 Oct 2007 16:41:37 -0700 Subject: memory hotplug: make kmem_cache_node for SLUB on memory online avoid panic Fix a panic due to access NULL pointer of kmem_cache_node at discard_slab() after memory online. When memory online is called, kmem_cache_nodes are created for all SLUBs for new node whose memory are available. slab_mem_going_online_callback() is called to make kmem_cache_node() in callback of memory online event. If it (or other callbacks) fails, then slab_mem_offline_callback() is called for rollback. In memory offline, slab_mem_going_offline_callback() is called to shrink all slub cache, then slab_mem_offline_callback() is called later. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: locking fix] [akpm@linux-foundation.org: build fix] Signed-off-by: Yasunori Goto Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/memory.h b/include/linux/memory.h index ec376e482ab..33f0ff0cf63 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -83,10 +83,14 @@ extern int memory_notify(unsigned long val, void *v); #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ +#ifdef CONFIG_MEMORY_HOTPLUG #define hotplug_memory_notifier(fn, pri) { \ static struct notifier_block fn##_mem_nb = \ { .notifier_call = fn, .priority = pri }; \ register_memory_notifier(&fn##_mem_nb); \ } +#else +#define hotplug_memory_notifier(fn, pri) do { } while (0) +#endif #endif /* _LINUX_MEMORY_H_ */ -- cgit v1.2.3-18-g5258