From patchwork Sat Oct 7 05:06:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yajun Deng X-Patchwork-Id: 13412190 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3A3DE523B for ; Sat, 7 Oct 2023 05:06:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="QvEOrQlh" Received: from out-193.mta1.migadu.com (out-193.mta1.migadu.com [IPv6:2001:41d0:203:375::c1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08F8FC2 for ; Fri, 6 Oct 2023 22:06:40 -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=1696655199; 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=q7I3d9LwjafU5Kv12eU37aaf8qZaT/OjOVOphwidH2Y=; b=QvEOrQlhdKmpbmzesqy3Qzfk18HpjUCqpVfC2Qd5xNkN+I/tGZMybjRDTXE50F/ZLECqcg Tw//uSdQORQPNXsUcPAo10ISuHPuhYdKt1rpXAvAwfNiaFHMZv7YMAlUv+zQ17weCYWoU8 l4S+si4z35nG0b08FnXFpkU9iM1xPn0= 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 net-next v7] net/core: Introduce netdev_core_stats_inc() Date: Sat, 7 Oct 2023 13:06:21 +0800 Message-Id: <20231007050621.1706331-1-yajun.deng@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org 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 dev_core_stats_*_inc(). Also, add __code to netdev_core_stats_alloc(), as it's called unlinkly. Signed-off-by: Yajun Deng Suggested-by: Alexander Lobakin --- v7: use WRITE_ONCE and READ_ONCE instead of '++' 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_*_inc() 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@linux.dev/ --- include/linux/netdevice.h | 21 ++++----------------- net/core/dev.c | 20 ++++++++++++++++++-- 2 files changed, 22 insertions(+), 19 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index e070a4540fba..11d704bfec9b 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4002,32 +4002,19 @@ static __always_inline bool __is_skb_forwardable(const struct net_device *dev, return false; } -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 = 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); #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 = 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 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..a38ea90771f5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10497,7 +10497,8 @@ void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64, } EXPORT_SYMBOL(netdev_stats_to_stats64); -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_alloc( + struct net_device *dev) { struct net_device_core_stats __percpu *p; @@ -10510,7 +10511,22 @@ 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 = READ_ONCE(dev->core_stats); + unsigned long *field; + + if (unlikely(!p)) + p = netdev_core_stats_alloc(dev); + + if (p) { + field = (unsigned long *)((void *)this_cpu_ptr(p) + offset); + WRITE_ONCE(*field, READ_ONCE(*field) + 1); + } +} +EXPORT_SYMBOL_GPL(netdev_core_stats_inc); /** * dev_get_stats - get network device statistics