From nobody Tue Dec 16 19:53:34 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47D3ECE7B10 for ; Thu, 28 Sep 2023 10:04:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230450AbjI1KEq (ORCPT ); Thu, 28 Sep 2023 06:04:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230320AbjI1KEp (ORCPT ); Thu, 28 Sep 2023 06:04:45 -0400 Received: from out-191.mta1.migadu.com (out-191.mta1.migadu.com [95.215.58.191]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04DF895 for ; Thu, 28 Sep 2023 03:04:41 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1695895480; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Aw98XHwV4z0PxcVRxJq+PgUKGG9cHNgr+8sDuBaS/1Q=; b=TBb/rvo4iC5NqzUiXAVJQLeGsn6GGRPy0R0UkLLMRmkRNBF0HbzkNMfNirj/11yxliPIab WfzLsmayk/t3sK6Udti6nVip0XT0zFJuEm8E3sZbMLPsAdA7EYG/SKUu4J53K58rxvBOYz Dk4VQl/feq6BmK6XhRu5P+mXndxuwEk= From: Yajun Deng To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Yajun Deng , Alexander Lobakin Subject: [PATCH v6] net/core: Introduce netdev_core_stats_inc() Date: Thu, 28 Sep 2023 18:04:18 +0800 Message-Id: <20230928100418.521594-1-yajun.deng@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Although there is a kfree_skb_reason() helper function that can be used to find the reason why this skb is dropped, but most callers didn't increase one of rx_dropped, tx_dropped, rx_nohandler and rx_otherhost_dropped. For the users, people are more concerned about why the dropped in ip is increasing. Introduce netdev_core_stats_inc() for trace the caller of the dropped skb. Also, add __code to netdev_core_stats_alloc(), as it's called unlinkly. Signed-off-by: Yajun Deng Suggested-by: Alexander Lobakin --- v6: merge netdev_core_stats and netdev_core_stats_inc together v5: Access the per cpu pointer before reach the relevant offset. v4: Introduce netdev_core_stats_inc() instead of export dev_core_stats_*_in= c() v3: __cold should be added to the netdev_core_stats_alloc(). v2: use __cold instead of inline in dev_core_stats(). v1: https://lore.kernel.org/netdev/20230911082016.3694700-1-yajun.deng@linu= x.dev/ --- include/linux/netdevice.h | 21 ++++----------------- net/core/dev.c | 17 +++++++++++++++-- 2 files changed, 19 insertions(+), 19 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 7e520c14eb8c..eb1fa04fbccc 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4002,32 +4002,19 @@ static __always_inline bool __is_skb_forwardable(co= nst struct net_device *dev, return false; } =20 -struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_= device *dev); - -static inline struct net_device_core_stats __percpu *dev_core_stats(struct= net_device *dev) -{ - /* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */ - struct net_device_core_stats __percpu *p =3D READ_ONCE(dev->core_stats); - - if (likely(p)) - return p; - - return netdev_core_stats_alloc(dev); -} +void netdev_core_stats_inc(struct net_device *dev, u32 offset); =20 #define DEV_CORE_STATS_INC(FIELD) \ static inline void dev_core_stats_##FIELD##_inc(struct net_device *dev) \ { \ - struct net_device_core_stats __percpu *p; \ - \ - p =3D dev_core_stats(dev); \ - if (p) \ - this_cpu_inc(p->FIELD); \ + netdev_core_stats_inc(dev, \ + offsetof(struct net_device_core_stats, FIELD)); \ } DEV_CORE_STATS_INC(rx_dropped) DEV_CORE_STATS_INC(tx_dropped) DEV_CORE_STATS_INC(rx_nohandler) DEV_CORE_STATS_INC(rx_otherhost_dropped) +#undef DEV_CORE_STATS_INC =20 static __always_inline int ____dev_forward_skb(struct net_device *dev, struct sk_buff *skb, diff --git a/net/core/dev.c b/net/core/dev.c index 606a366cc209..88a32c392c1d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10497,7 +10497,8 @@ void netdev_stats_to_stats64(struct rtnl_link_stats= 64 *stats64, } EXPORT_SYMBOL(netdev_stats_to_stats64); =20 -struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_= device *dev) +static __cold struct net_device_core_stats __percpu *netdev_core_stats_all= oc( + struct net_device *dev) { struct net_device_core_stats __percpu *p; =20 @@ -10510,7 +10511,19 @@ struct net_device_core_stats __percpu *netdev_core= _stats_alloc(struct net_device /* This READ_ONCE() pairs with the cmpxchg() above */ return READ_ONCE(dev->core_stats); } -EXPORT_SYMBOL(netdev_core_stats_alloc); + +void netdev_core_stats_inc(struct net_device *dev, u32 offset) +{ + /* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */ + struct net_device_core_stats __percpu *p =3D READ_ONCE(dev->core_stats); + + if (unlikely(!p)) + p =3D netdev_core_stats_alloc(dev); + + if (p) + (*(unsigned long *)((void *)this_cpu_ptr(p) + offset))++; +} +EXPORT_SYMBOL_GPL(netdev_core_stats_inc); =20 /** * dev_get_stats - get network device statistics --=20 2.25.1