[PATCH v6 net-next 09/11] skbuff: allow to optionally use NAPI cache from __alloc_skb()

[Alexander Lobakin]

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@xxxxxxxxx> # Simplified flags check
Signed-off-by: Alexander Lobakin <alobakin@xxxxx>
---
 net/core/skbuff.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 9e1a8ded4acc..a80581eed7fc 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -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);
-- 
2.30.1