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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 DA19FC433E0 for ; Tue, 23 Feb 2021 13:55:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9624964E61 for ; Tue, 23 Feb 2021 13:55:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232113AbhBWNzX (ORCPT ); Tue, 23 Feb 2021 08:55:23 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:44677 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232553AbhBWNzV (ORCPT ); Tue, 23 Feb 2021 08:55:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614088435; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kwir4Wsil0jK4OKrvTzT1wqhvatcr2vaWyMIyN42ByU=; b=JSh90TEyuqBtV2DIpGKGf1RZi7yhQVTjLMMLhiqu1lusQlPZkl98y5/piN/jnqt08rLbCc vB9mqJk17C2PU4uWpCeQPiwkm0sYUQJAGyr82L5X3/As4c0TEqwYG++Lbsy/ZBIcECvmJG NvONh07PGbCJ3c37Q2Wvl7pj0o1pim8= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-116-10HtXWR3N62sHuntM-s8mQ-1; Tue, 23 Feb 2021 08:53:44 -0500 X-MC-Unique: 10HtXWR3N62sHuntM-s8mQ-1 Received: by mail-wm1-f70.google.com with SMTP id r21so684680wmq.7 for ; Tue, 23 Feb 2021 05:53:44 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=kwir4Wsil0jK4OKrvTzT1wqhvatcr2vaWyMIyN42ByU=; b=FeFLEr6EoeKqqsJFKUjmjXbZyfM/ugjyTcDToZvhKVWd5/12Mz57e6dz6dQ6bhhGX4 s2382jBAk44FfAlgmEkEeCvDnnmoHqh+V+UIhxxfTF1SqKZQmlqUKLwK/6hI1Ed2gLfA 97msbeMaulJIwKHQT28Gws5EODR1UBXVcnzgmG/5rPCNPgAVpJxCaBtVgK2znzwWcVoF dl/LcGTh3nZIDAoAMiyWyBt6hYkEgRuQv+AoRZSrFqDlVNCMJ6+HeYAyBFVBaU6LONte F07Jb0T3JpZR5evx+kswudEzOcJwgqQG2zcvZKWLLzT80k6u22MuWmLsN3c+B34Pyf1R yhAw== X-Gm-Message-State: AOAM533qidyrl21ND9ZNo1VvIUoJMK0LFs+Wf/nwc7VCSxcnOJomKou1 vQSWKlHu4AxaGu7/VaWLNdW2BYOjtcLGOD4qvD/kzIDIzZ29TnXAvCMdy9Bhi8Bl6d7JSqQWOc6 0nj4x00CjKAKuSXWnSiVb97sMeLs= X-Received: by 2002:a5d:6281:: with SMTP id k1mr234361wru.405.1614088423228; Tue, 23 Feb 2021 05:53:43 -0800 (PST) X-Google-Smtp-Source: ABdhPJwvqa5mYS76mtgwFOwEo0awuiMGbxRj6wFrWqOCDoWYiXdsOnm2PzYL52S+dUZeC9KAg4PB0w== X-Received: by 2002:a5d:6281:: with SMTP id k1mr234355wru.405.1614088423062; Tue, 23 Feb 2021 05:53:43 -0800 (PST) Received: from localhost.localdomain ([151.29.106.174]) by smtp.gmail.com with ESMTPSA id w4sm2749376wmc.13.2021.02.23.05.53.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Feb 2021 05:53:42 -0800 (PST) Date: Tue, 23 Feb 2021 14:53:40 +0100 From: Juri Lelli To: Sebastian Andrzej Siewior Cc: linux-rt-users , LKML , "Ahmed S. Darwish" , Peter Zijlstra Subject: Re: [RT v5.11-rt7] WARNING at include/linux/seqlock.h:271 nft_counter_eval Message-ID: References: <20210223110015.ybl7feu43wvtjoqu@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210223110015.ybl7feu43wvtjoqu@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On 23/02/21 12:00, Sebastian Andrzej Siewior wrote: > On 2021-02-23 11:49:07 [+0100], Juri Lelli wrote: > > Hi, > Hi, > > > I'm seeing the following splat right after boot (or during late boot > > phases) with v5.11-rt7 (LOCKDEP enabled). > … > > [ 85.273588] WARNING: CPU: 5 PID: 1416 at include/linux/seqlock.h:271 nft_counter_eval+0x95/0x130 [nft_counter] > … > > [ 85.273713] RIP: 0010:nft_counter_eval+0x95/0x130 [nft_counter] > > This is a per-CPU seqcount_t in net/netfilter/nft_counter.c which is > only protected by local_bh_disabled(). The warning expects preemption > to be disabled which is the case on !RT but not on RT. > > Not sure what to do about this. It is doing anything wrong as of now. It > is noisy. So, I'm a bit confused and I'm very likely missing details (still digesting the seqprop_ magic), but write_seqcount_being() has if (seqprop_preemptible(s)) preempt_disable(); which in this case (no lock associated) is defined to return false, while it should return true on RT (or in some occasions)? Or maybe this is what you are saying already. Also, the check for preemption been disabled happens before we can actually potentially disable it, no? Thanks for the quick reply! Best, Juri