Subject: node-aware skb allocation

Note: needs benchmarking to prove a gain.

Note2:  Needs to API rework before upstream submission

Signed-off-by: Christoph Hellwig <chellwig@de.ibm.com>

Index: linux-2.6/include/linux/skbuff.h
===================================================================
--- linux-2.6.orig/include/linux/skbuff.h
+++ linux-2.6/include/linux/skbuff.h
@@ -330,17 +330,17 @@ struct sk_buff {
 extern void kfree_skb(struct sk_buff *skb);
 extern void	       __kfree_skb(struct sk_buff *skb);
 extern struct sk_buff *__alloc_skb(unsigned int size,
-				   gfp_t priority, int fclone);
+				   gfp_t priority, int fclone, int node);
 static inline struct sk_buff *alloc_skb(unsigned int size,
 					gfp_t priority)
 {
-	return __alloc_skb(size, priority, 0);
+	return __alloc_skb(size, priority, 0, -1);
 }
 
 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
 					       gfp_t priority)
 {
-	return __alloc_skb(size, priority, 1);
+	return __alloc_skb(size, priority, 1, -1);
 }
 
 extern struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp,
@@ -1107,6 +1107,15 @@ static inline struct sk_buff *__dev_allo
 	return skb;
 }
 
+static inline struct sk_buff *dev_alloc_skb_node(unsigned int length, int node)
+{
+	struct sk_buff *skb = __alloc_skb(length + NET_SKB_PAD,
+			GFP_ATOMIC, 0, node);
+	if (likely(skb))
+		skb_reserve(skb, NET_SKB_PAD);
+	return skb;
+}
+
 /**
  *	dev_alloc_skb - allocate an skbuff for receiving
  *	@length: length to allocate
Index: linux-2.6/net/core/skbuff.c
===================================================================
--- linux-2.6.orig/net/core/skbuff.c
+++ linux-2.6/net/core/skbuff.c
@@ -131,6 +131,7 @@ EXPORT_SYMBOL(skb_truesize_bug);
  *	@gfp_mask: allocation mask
  *	@fclone: allocate from fclone cache instead of head cache
  *		and allocate a cloned (child) skb
+ *	@node: numa node to allocate memory on
  *
  *	Allocate a new &sk_buff. The returned buffer has no headroom and a
  *	tail room of size bytes. The object has a reference count of one.
@@ -140,7 +141,7 @@ EXPORT_SYMBOL(skb_truesize_bug);
  *	%GFP_ATOMIC.
  */
 struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
-			    int fclone)
+			    int fclone, int node)
 {
 	kmem_cache_t *cache;
 	struct skb_shared_info *shinfo;
@@ -150,13 +151,15 @@ struct sk_buff *__alloc_skb(unsigned int
 	cache = fclone ? skbuff_fclone_cache : skbuff_head_cache;
 
 	/* Get the HEAD */
-	skb = kmem_cache_alloc(cache, gfp_mask & ~__GFP_DMA);
+	skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node);
 	if (!skb)
 		goto out;
 
 	/* Get the DATA. Size must match skb_add_mtu(). */
 	size = SKB_DATA_ALIGN(size);
-	data = ____kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
+//	data = ____kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
+	data = kmalloc_node(size + sizeof(struct skb_shared_info),
+			gfp_mask, node);
 	if (!data)
 		goto nodata;