From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82BFCC433E7 for ; Sun, 18 Oct 2020 23:18:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 403DB21D7F for ; Sun, 18 Oct 2020 23:18:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hmamVEH1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729591AbgJRXLZ (ORCPT ); Sun, 18 Oct 2020 19:11:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726681AbgJRXLY (ORCPT ); Sun, 18 Oct 2020 19:11:24 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC961C061755 for ; Sun, 18 Oct 2020 16:11:22 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id l18so4931322pgg.0 for ; Sun, 18 Oct 2020 16:11:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=ZC2XV0rDP18emYrvaZPnFix73dSXeyGVbU3UcjNBAJE=; b=hmamVEH1dkEzDAva9KAmEJG2A+E3d6BmAwv/z1P5G044cZkjxXib9Mr6u0tHcUcesS JNAZXSCTUzjKB6WCQl7WL1bp6DbzxQUH6fM4j36mcQ0v3lTPtucVSxzXsisGf7Ocobqg QsTkFr2a1kYMRJdk0HOQNRqF7TRKq2gFOt5ZaE4HTkx7YqhYgnfty8WT9t8vRGDqi6uV HnDoNpnxD58onuYiWED7AfmOYqGqg8vHGpCJ1LEobuMh2lPTCu5LWLwfsSm7GzO7mJoZ DEImxxgPP8Cou+HzRs1C6fGvU/7CNUhCn80myZ34FCGWPGJIc/ulMIKbUJcLMqJdy3uK jhdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ZC2XV0rDP18emYrvaZPnFix73dSXeyGVbU3UcjNBAJE=; b=I1lqObMNjWLxzTLqGJNpss1wE1GbbGXh8xMtEqwbF7dDaU5FAfEMp9J8r6dX42T5aB To0SKE57oI3PnHWeCBpRakAKJppcOPPEgPdmITS/2EVbXZdNw3aH1n1/8t1okFR9oAdZ lvyACuTkQLarSjw3ONCpeDaEy4D/s69sFZYUy1l+0QnWdJpLAXEJtqnO3DxPyxMgC0z5 NiC4e7RDrqOBwoEmlt4vFgQWcnwiFh4SxZiTTATFXGvco+oKPyNJSLVq0ep+CCksA0FG hPMcoLRa/thvShk8QsTsHTpYjUSZENfswnKlMfKOHuR70S17wfpNNZtFy1pB8rqo2lJJ z2pw== X-Gm-Message-State: AOAM5304wwn2SdpAjWPaDLki72c49Tnnq+bcxmV+TXoIBJLY1K8COfPQ lhk9EObyQ/+0YQ4sI62RvAA= X-Google-Smtp-Source: ABdhPJxTI2I+NpC/N5TYVJR/VEmrDIoUQ8OjZMuSGY83wZtS7Mjn0YMTEjJ9F54QpLsN2AtNnMp1kg== X-Received: by 2002:a63:9508:: with SMTP id p8mr11987436pgd.189.1603062682173; Sun, 18 Oct 2020 16:11:22 -0700 (PDT) Received: from [10.230.29.112] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id t6sm9839548pfl.50.2020.10.18.16.11.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 18 Oct 2020 16:11:21 -0700 (PDT) Subject: Re: [RFC PATCH 01/13] net: dsa: add plumbing for custom netdev statistics To: Vladimir Oltean , Heiner Kallweit Cc: "netdev@vger.kernel.org" , "andrew@lunn.ch" , "vivien.didelot@gmail.com" , "kuba@kernel.org" , Christian Eggers , Kurt Kanzenbach References: <20201017213611.2557565-1-vladimir.oltean@nxp.com> <20201017213611.2557565-2-vladimir.oltean@nxp.com> <06538edb-65a9-c27f-2335-9213322bed3a@gmail.com> <20201018121640.jwzj6ivpis4gh4ki@skbuf> <19f10bf4-4154-2207-6554-e44ba05eed8a@gmail.com> <20201018134843.emustnvgyby32cm4@skbuf> <2ae30988-5918-3d02-87f1-e65942acc543@gmail.com> <20201018225820.b2vhgzyzwk7vy62j@skbuf> From: Florian Fainelli Message-ID: Date: Sun, 18 Oct 2020 16:11:14 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.3.2 MIME-Version: 1.0 In-Reply-To: <20201018225820.b2vhgzyzwk7vy62j@skbuf> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 10/18/2020 3:58 PM, Vladimir Oltean wrote: > On Sun, Oct 18, 2020 at 04:13:28PM +0200, Heiner Kallweit wrote: >> On a side note, because I'm also just dealing with it: this_cpu_ptr() >> is safe only if preemption is disabled. Is this the case here? Else >> there's get_cpu_ptr/put_cpu_ptr. > > lockdep would shout about using smp_processor_id() in preemptible > context? Because it doesn't do that, and never did, but I don't really > understand why, coming to think of it. > >> Also, if irq's aren't disabled there might be a need to use >> u64_stats_update_begin_irqsave() et al. See: 2695578b896a ("net: >> usbnet: fix potential deadlock on 32bit hosts") But I don't know dsa >> good enough to say whether this is applicable here. > > DSA xmit and receive path do not run from hardirq context, just softirq, > so I believe the issue reported to Eric there does not apply here. How about when used as a netconsole? We do support netconsole over DSA interfaces. -- Florian