From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 13 Jun 2007 15:46:11 -0700 (PDT) From: Christoph Lameter Subject: Re: [patch 2/3] Fix GFP_THISNODE behavior for memoryless nodes In-Reply-To: <1181769033.6148.116.camel@localhost> Message-ID: References: <20070612204843.491072749@sgi.com> <20070612205738.548677035@sgi.com> <1181769033.6148.116.camel@localhost> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Lee Schermerhorn Cc: akpm@linux-foundation.org, linux-mm@kvack.org, ak@suse.de, Nishanth Aravamudan List-ID: On Wed, 13 Jun 2007, Lee Schermerhorn wrote: > SLUB early allocation, included in the patch. Works on HP ia64 platform > with small DMA only node and "zone order" zonelists. Will test on > x86_64 real soon now... I do not see the difference?? How does this work? node_memory(x) fails there? > The map of nodes with memory may include nodes with just > DMA/DMA32 memory. Using this map/mask together with > GFP_THISNODE will not guarantee on-node allocations at higher > zones. Modify checks in alloc_pages_node() to ensure that the > first zone in the selected zonelist is "on-node". That check is already done by __alloc_pages. > This change will result in alloc_pages_node() returning NULL > when GFP_THISNODE is specified and the first zone in the zonelist > selected by (nid, gfp_zone(gfp_mask) is not on node 'nid'. This, > in turn, BUGs out in slub.c:early_kmem_cache_node_alloc() which > apparently can't handle a NULL page from new_slab(). Fix SLUB > to handle NULL page in early allocation. Ummm... Slub would need to consult node_memory_map instead I guess. > Index: Linux/mm/slub.c > =================================================================== > --- Linux.orig/mm/slub.c 2007-06-13 16:36:02.000000000 -0400 > +++ Linux/mm/slub.c 2007-06-13 16:38:41.000000000 -0400 > @@ -1870,16 +1870,18 @@ static struct kmem_cache_node * __init e > /* new_slab() disables interupts */ > local_irq_enable(); > > - BUG_ON(!page); > - n = page->freelist; > - BUG_ON(!n); > - page->freelist = get_freepointer(kmalloc_caches, n); > - page->inuse++; > - kmalloc_caches->node[node] = n; > - setup_object_debug(kmalloc_caches, page, n); > - init_kmem_cache_node(n); > - atomic_long_inc(&n->nr_slabs); > - add_partial(n, page); > + if (page) { > + n = page->freelist; > + BUG_ON(!n); > + page->freelist = get_freepointer(kmalloc_caches, n); > + page->inuse++; > + kmalloc_caches->node[node] = n; > + setup_object_debug(kmalloc_caches, page, n); > + init_kmem_cache_node(n); > + atomic_long_inc(&n->nr_slabs); > + add_partial(n, page); > + } else > + kmalloc_caches->node[node] = NULL; > return n; > } It would be easier to modify SLUB to loop over node_memory_map instead of node_online_map? Potentially we have to change all loops over online node in the slab allocators. --- include/linux/nodemask.h | 1 + mm/slub.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) Index: linux-2.6/include/linux/nodemask.h =================================================================== --- linux-2.6.orig/include/linux/nodemask.h 2007-06-13 15:40:27.000000000 -0700 +++ linux-2.6/include/linux/nodemask.h 2007-06-13 15:40:48.000000000 -0700 @@ -377,5 +377,6 @@ extern int nr_node_ids; #define for_each_node(node) for_each_node_mask((node), node_possible_map) #define for_each_online_node(node) for_each_node_mask((node), node_online_map) +#define for_each_memory_node(node) for_each_node_mask((node), node_memory_map) #endif /* __LINUX_NODEMASK_H */ Index: linux-2.6/mm/slub.c =================================================================== --- linux-2.6.orig/mm/slub.c 2007-06-13 15:39:16.000000000 -0700 +++ linux-2.6/mm/slub.c 2007-06-13 15:40:23.000000000 -0700 @@ -1836,7 +1836,7 @@ static int init_kmem_cache_nodes(struct else local_node = 0; - for_each_online_node(node) { + for_each_memory_node(node) { struct kmem_cache_node *n; if (local_node == node) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org