skbuff: allow to optionally use NAPI cache from __alloc_skb()

Reuse the old and forgotten SKB_ALLOC_NAPI to add an option to get
an skbuff_head from the NAPI cache instead of inplace allocation
inside __alloc_skb().
This implies that the function is called from softirq or BH-off
context, not for allocating a clone or from a distant node.

Cc: Alexander Duyck <alexander.duyck@gmail.com> # Simplified flags check
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexander Lobakin 2021-02-13 14:12:38 +00:00 committed by David S. Miller
parent f450d539c0
commit d13612b58e

View file

@ -405,7 +405,11 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
gfp_mask |= __GFP_MEMALLOC;
/* Get the HEAD */
skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node);
if ((flags & (SKB_ALLOC_FCLONE | SKB_ALLOC_NAPI)) == SKB_ALLOC_NAPI &&
likely(node == NUMA_NO_NODE || node == numa_mem_id()))
skb = napi_skb_cache_get();
else
skb = kmem_cache_alloc_node(cache, gfp_mask & ~GFP_DMA, node);
if (unlikely(!skb))
return NULL;
prefetchw(skb);