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[23.128.96.33]) by mx.google.com with ESMTPS id h6-20020a056a001a4600b006910a45a234si7250960pfv.202.2023.10.09.04.17.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Oct 2023 04:17:22 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) client-ip=23.128.96.33; Authentication-Results: mx.google.com; dkim=pass header.i=@linux.dev header.s=key1 header.b=BwdVQ61i; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.dev Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by lipwig.vger.email (Postfix) with ESMTP id AE2428053639; Mon, 9 Oct 2023 04:17:20 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at lipwig.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346187AbjJILQz (ORCPT + 18 others); Mon, 9 Oct 2023 07:16:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345822AbjJILQy (ORCPT ); Mon, 9 Oct 2023 07:16:54 -0400 Received: from out-208.mta1.migadu.com (out-208.mta1.migadu.com [IPv6:2001:41d0:203:375::d0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DB2A94 for ; Mon, 9 Oct 2023 04:16:52 -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=1696850210; 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=iXX/1lVwKrWymkXfI3JV+KmeWnDZTSV8t81NoepFl1M=; b=BwdVQ61iisKUdcwp0cDeBS0BaWp7Pr84P53tpMsWcjG+HUU5Q2ey3f2+yPAUS4O0v8Gfhq aKGeOfXjgI6U8TGTA4jtmejSuvMmAiPvO99YXzaxs9UemrP7Yzrzf94lDg5aPzBpQx/CkQ JGCuupGlyLGYtrE77U2KO4zCoWX9kso= 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 v8] net/core: Introduce netdev_core_stats_inc() Date: Mon, 9 Oct 2023 19:16:33 +0800 Message-Id: <20231009111633.2319304-1-yajun.deng@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Spam-Status: No, score=2.7 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_SBL_CSS,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lipwig.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (lipwig.vger.email [0.0.0.0]); Mon, 09 Oct 2023 04:17:20 -0700 (PDT) X-Spam-Level: ** X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1779072649696483101 X-GMAIL-MSGID: 1779276439968649945 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 with small probability. And add noinline make sure netdev_core_stats_inc was never inlined. Signed-off-by: Yajun Deng Suggested-by: Alexander Lobakin Reviewed-by: Eric Dumazet --- v8: use noinline and this_cpu_inc in netdev_core_stats_inc. 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 | 21 +++++++++++++++++++-- 2 files changed, 23 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..02949a929e7f 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 +10511,23 @@ 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); + +noinline 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 __percpu *field; + + if (unlikely(!p)) { + p = netdev_core_stats_alloc(dev); + if (!p) + return; + } + + field = (__force unsigned long __percpu *)((__force void *)p + offset); + this_cpu_inc(*field); +} +EXPORT_SYMBOL_GPL(netdev_core_stats_inc); /** * dev_get_stats - get network device statistics