skbuff: queue NAPI_MERGED_FREE skbs into NAPI cache instead of freeing

napi_frags_finish() and napi_skb_finish() can only be called inside NAPI Rx context, so we can feed NAPI cache with skbuff_heads that got NAPI_MERGED_FREE verdict instead of immediate freeing. Replace __kfree_skb() with __kfree_skb_defer() in napi_skb_finish() and move napi_skb_free_stolen_head() to skbuff.c, so it can drop skbs to NAPI cache. As many drivers call napi_alloc_skb()/napi_get_frags() on their receive path, this becomes especially useful. Signed-off-by: Alexander Lobakin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
0day-ci · Feb 13, 2021 · 9243adf · 9243adf
1 parent cfb8ec6
commit 9243adf
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Showing 3 changed files with 11 additions and 11 deletions.
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
@@ -2921,6 +2921,7 @@ static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
 }
 void napi_consume_skb(struct sk_buff *skb, int budget);
 
+void napi_skb_free_stolen_head(struct sk_buff *skb);
 void __kfree_skb_defer(struct sk_buff *skb);
 
 /**

diff --git a/net/core/dev.c b/net/core/dev.c
@@ -6095,13 +6095,6 @@ struct packet_offload *gro_find_complete_by_type(__be16 type)
 }
 EXPORT_SYMBOL(gro_find_complete_by_type);
 
-static void napi_skb_free_stolen_head(struct sk_buff *skb)
-{
-	skb_dst_drop(skb);
-	skb_ext_put(skb);
-	kmem_cache_free(skbuff_head_cache, skb);
-}
-
 static gro_result_t napi_skb_finish(struct napi_struct *napi,
 				    struct sk_buff *skb,
 				    gro_result_t ret)
@@ -6115,7 +6108,7 @@ static gro_result_t napi_skb_finish(struct napi_struct *napi,
 		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
 			napi_skb_free_stolen_head(skb);
 		else
-			__kfree_skb(skb);
+			__kfree_skb_defer(skb);
 		break;
 
 	case GRO_HELD:

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
@@ -916,9 +916,6 @@ static void napi_skb_cache_put(struct sk_buff *skb)
 	struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
 	u32 i;
 
-	/* drop skb->head and call any destructors for packet */
-	skb_release_all(skb);
-
 	kasan_poison_object_data(skbuff_head_cache, skb);
 	nc->skb_cache[nc->skb_count++] = skb;
 
@@ -935,6 +932,14 @@ static void napi_skb_cache_put(struct sk_buff *skb)
 
 void __kfree_skb_defer(struct sk_buff *skb)
 {
+	skb_release_all(skb);
+	napi_skb_cache_put(skb);
+}
+
+void napi_skb_free_stolen_head(struct sk_buff *skb)
+{
+	skb_dst_drop(skb);
+	skb_ext_put(skb);
 	napi_skb_cache_put(skb);
 }
 
@@ -960,6 +965,7 @@ void napi_consume_skb(struct sk_buff *skb, int budget)
 		return;
 	}
 
+	skb_release_all(skb);
 	napi_skb_cache_put(skb);
 }
 EXPORT_SYMBOL(napi_consume_skb);
-Original file line number
+Diff line change
@@ Expand Up @@
     }
     void napi_consume_skb(struct sk_buff *skb, int budget);
+    void napi_skb_free_stolen_head(struct sk_buff *skb);
     void __kfree_skb_defer(struct sk_buff *skb);
     /**
@@ Expand Down @@