From: Eric Dumazet <edumazet@xxxxxxxxxx>
commit 115f1a5c42bdad9a9ea356fc0b4a39ec7537947f upstream.
We have many places using this expression:
SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
Use of SKB_HEAD_ALIGN() will allow to clean them.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Acked-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Alexander Duyck <alexanderduyck@xxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
[Ajay: Regenerated the patch for v6.1.y]
Signed-off-by: Ajay Kaher <akaher@xxxxxxxxxx>
---
include/linux/skbuff.h | 8 ++++++++
net/core/skbuff.c | 18 ++++++------------
2 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index cc5ed2c..2feee14 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -261,6 +261,14 @@
#define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
#define SKB_WITH_OVERHEAD(X) \
((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
+
+/* For X bytes available in skb->head, what is the minimal
+ * allocation needed, knowing struct skb_shared_info needs
+ * to be aligned.
+ */
+#define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
+
#define SKB_MAX_ORDER(X, ORDER) \
SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 24bf4aa..4aea8f5 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -504,8 +504,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
* aligned memory blocks, unless SLUB/SLAB debug is enabled.
* Both skb->head and skb_shared_info are cache line aligned.
*/
- size = SKB_DATA_ALIGN(size);
- size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ size = SKB_HEAD_ALIGN(size);
osize = kmalloc_size_roundup(size);
data = kmalloc_reserve(osize, gfp_mask, node, &pfmemalloc);
if (unlikely(!data))
@@ -578,8 +577,7 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len,
goto skb_success;
}
- len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
- len = SKB_DATA_ALIGN(len);
+ len = SKB_HEAD_ALIGN(len);
if (sk_memalloc_socks())
gfp_mask |= __GFP_MEMALLOC;
@@ -678,8 +676,7 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len,
data = page_frag_alloc_1k(&nc->page_small, gfp_mask);
pfmemalloc = NAPI_SMALL_PAGE_PFMEMALLOC(nc->page_small);
} else {
- len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
- len = SKB_DATA_ALIGN(len);
+ len = SKB_HEAD_ALIGN(len);
data = page_frag_alloc(&nc->page, len, gfp_mask);
pfmemalloc = nc->page.pfmemalloc;
@@ -1837,8 +1834,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
if (skb_pfmemalloc(skb))
gfp_mask |= __GFP_MEMALLOC;
- size = SKB_DATA_ALIGN(size);
- size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ size = SKB_HEAD_ALIGN(size);
size = kmalloc_size_roundup(size);
data = kmalloc_reserve(size, gfp_mask, NUMA_NO_NODE, NULL);
if (!data)
@@ -6204,8 +6200,7 @@ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off,
if (skb_pfmemalloc(skb))
gfp_mask |= __GFP_MEMALLOC;
- size = SKB_DATA_ALIGN(size);
- size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ size = SKB_HEAD_ALIGN(size);
size = kmalloc_size_roundup(size);
data = kmalloc_reserve(size, gfp_mask, NUMA_NO_NODE, NULL);
if (!data)
@@ -6323,8 +6318,7 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off,
if (skb_pfmemalloc(skb))
gfp_mask |= __GFP_MEMALLOC;
- size = SKB_DATA_ALIGN(size);
- size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ size = SKB_HEAD_ALIGN(size);
size = kmalloc_size_roundup(size);
data = kmalloc_reserve(size, gfp_mask, NUMA_NO_NODE, NULL);
if (!data)
--
2.7.4
