diff options
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 5b2c5f1d4dba..a7f855dca922 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -184,11 +184,20 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, goto out; prefetchw(skb); - size = SKB_DATA_ALIGN(size); - data = kmalloc_node_track_caller(size + sizeof(struct skb_shared_info), - gfp_mask, node); + /* We do our best to align skb_shared_info on a separate cache + * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives + * aligned memory blocks, unless SLUB/SLAB debug is enabled. + * Both skb->head and skb_shared_info are cache line aligned. + */ + size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + data = kmalloc_node_track_caller(size, gfp_mask, node); if (!data) goto nodata; + /* kmalloc(size) might give us more room than requested. + * Put skb_shared_info exactly at the end of allocated zone, + * to allow max possible filling before reallocation. + */ + size = SKB_WITH_OVERHEAD(ksize(data)); prefetchw(data + size); /* @@ -197,7 +206,8 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, * the tail pointer in struct sk_buff! */ memset(skb, 0, offsetof(struct sk_buff, tail)); - skb->truesize = size + sizeof(struct sk_buff); + /* Account for allocated memory : skb + skb->head */ + skb->truesize = SKB_TRUESIZE(size); atomic_set(&skb->users, 1); skb->head = data; skb->data = data; |