diff mbox series

[v2,net-next,1/4] net: add SKB_HEAD_ALIGN() helper

Message ID 20230206173103.2617121-2-edumazet@google.com (mailing list archive)
State Accepted
Commit 115f1a5c42bdad9a9ea356fc0b4a39ec7537947f
Delegated to: Netdev Maintainers
Headers show
Series net: core: use a dedicated kmem_cache for skb head allocs | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5334 this patch: 5334
netdev/cc_maintainers warning 1 maintainers not CCed: imagedong@tencent.com
netdev/build_clang success Errors and warnings before: 1084 this patch: 1084
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5549 this patch: 5549
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 68 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet Feb. 6, 2023, 5:31 p.m. UTC 
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@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
---
 include/linux/skbuff.h |  8 ++++++++
 net/core/skbuff.c      | 18 ++++++------------
 2 files changed, 14 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1fa95b916342e77601803ba1056f2d2b0646517b..c3df3b55da976dba2f5ba72bfa692329479d6750 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -255,6 +255,14 @@ 
 #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 624e9e4ec116e2a619e49b3d8d8be7ece2ee41cc..4abfc3ba6898d89f4df97bf5f069b291dd5e420f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -558,8 +558,7 @@  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))
@@ -632,8 +631,7 @@  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;
@@ -732,8 +730,7 @@  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;
@@ -1938,8 +1935,7 @@  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)
@@ -6289,8 +6285,7 @@  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)
@@ -6408,8 +6403,7 @@  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)