From: Jason Xing <kernelxing@tencent.com>
Date: Tue, 18 Nov 2025 07:06:46 +0000 (+0800)
Subject: net: prefetch the next skb in napi_skb_cache_get()
X-Git-Tag: v6.19-rc1~170^2~117^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5d7fc63ab84182f75d5e73e299ce0e7c9c20c092;p=thirdparty%2Fkernel%2Flinux.git

net: prefetch the next skb in napi_skb_cache_get()

After getting the current skb in napi_skb_cache_get(), the next skb in
cache is highly likely to be used soon, so prefetch would be helpful.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20251118070646.61344-5-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d81ac78c32ffc..5a1d123e7ef74 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -299,6 +299,8 @@ static struct sk_buff *napi_skb_cache_get(bool alloc)
 	}
 
 	skb = nc->skb_cache[--nc->skb_count];
+	if (nc->skb_count)
+		prefetch(nc->skb_cache[nc->skb_count - 1]);
 	local_unlock_nested_bh(&napi_alloc_cache.bh_lock);
 	kasan_mempool_unpoison_object(skb, skbuff_cache_size);