From 1db70eb9f76dae958db5a9bfc57803654debb6e4 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Thu, 25 Oct 2012 12:14:52 +1100 Subject: [PATCH] slub, hotplug: ignore unrelated node's hot-adding and hot-removing SLUB only focuses on the nodes which have normal memory and it ignores the other node's hot-adding and hot-removing. Aka: if some memory of a node which has no onlined memory is online, but this new memory onlined is not normal memory (for example, highmem), we should not allocate kmem_cache_node for SLUB. And if the last normal memory is offlined, but the node still has memory, we should remove kmem_cache_node for that node. (The current code delays it when all of the memory is offlined) So we only do something when marg->status_change_nid_normal > 0. marg->status_change_nid is not suitable here. The same problem doesn't exist in SLAB, because SLAB allocates kmem_list3 for every node even the node don't have normal memory, SLAB tolerates kmem_list3 on alien nodes. SLUB only focuses on the nodes which have normal memory, it don't tolerate alien kmem_cache_node. The patch makes SLUB become self-compatible and avoids WARNs and BUGs in rare conditions. Signed-off-by: Lai Jiangshan Cc: David Rientjes Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Yasuaki Ishimatsu Cc: Rob Landley Cc: Andrew Morton Cc: Jiang Liu Cc: Kay Sievers Cc: Greg Kroah-Hartman Cc: Mel Gorman Cc: Wen Congyang Acked-by: Christoph Lameter Cc: Pekka Enberg Signed-off-by: Andrew Morton --- mm/slub.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index b2ada3db4225..097ac86a3606 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3555,7 +3555,7 @@ static void slab_mem_offline_callback(void *arg) struct memory_notify *marg = arg; int offline_node; - offline_node = marg->status_change_nid; + offline_node = marg->status_change_nid_normal; /* * If the node still has available memory. we need kmem_cache_node @@ -3588,7 +3588,7 @@ static int slab_mem_going_online_callback(void *arg) struct kmem_cache_node *n; struct kmem_cache *s; struct memory_notify *marg = arg; - int nid = marg->status_change_nid; + int nid = marg->status_change_nid_normal; int ret = 0; /* -- 2.39.5