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=-0.9 required=3.0 tests=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 D2094C3F2CD for ; Sun, 1 Mar 2020 22:18:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BAC2246A1 for ; Sun, 1 Mar 2020 22:18:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="f02XpK2e" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726603AbgCAWSs (ORCPT ); Sun, 1 Mar 2020 17:18:48 -0500 Received: from mail-il1-f195.google.com ([209.85.166.195]:38233 "EHLO mail-il1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726465AbgCAWSr (ORCPT ); Sun, 1 Mar 2020 17:18:47 -0500 Received: by mail-il1-f195.google.com with SMTP id f5so7658132ilq.5 for ; Sun, 01 Mar 2020 14:18:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=idl6CAZ4ITJuBYPn9L4mQrfqGQ3iPRLrH1VIVeU0Djc=; b=f02XpK2ejCZoNah0VS/D/BTPPXjnnwlxaKHbPLZ1gNzdM8WoIRfmLM97gRYrrkNYzb /4UEOO6pkK9VGFzE/xMp8jBkDU7yhZBwVQMTYnUPS6N5I0l3ISvaWhDH1glPSAAsCRCS 8YaVQcO/YyHQfzdaQOdKtLXt4hhcm3zjX+xPo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=idl6CAZ4ITJuBYPn9L4mQrfqGQ3iPRLrH1VIVeU0Djc=; b=anhPt8Du0jylS7ZAgCtrDhs/2t97CvMXhjbBX6TZuEDqCMGM1U/7zdGRI25ic+sw/F WK91E7iLqURFt/+Jzd+KC0SID/fUYnq0kn4/GwRF9oqn0hrNQ6gASTXPYrrp5aMnGSAH nUYehWZVFW8MuZO6OuPgq5BzArZgs+ydmIhkaokkxhUPSCdxsU518LvbKI+baX2ivqgH kXHCUbzn0n97ZhFL7CA3GREbWV2bp1KVHukwnYfQA1RUryhC1YHZBpMEPTuaB9yB8HgV ve7/xCTrlLGMJWR7cBQXQV9FESabsTCBFeLfk/ksLwxVnAnkx/Naw8tRxU7PxPPHMjha inLA== X-Gm-Message-State: APjAAAU9Du8pEuOlklHG7EWurvzkd6m9+TM5ptKBmrLWGC/sQHevAucu ZDCD+/TALsQJt05uxugT9qAwJ2fM9e6jboUgpof83w== X-Google-Smtp-Source: APXvYqwLnS0nfF1/cQS73Q2LPYiqa+EUG8rSDYv9Fre1Q/MkLceZD9/brJKRSb0IQJQPd3q9fUNP9keq8GFm1k6ZCHQ= X-Received: by 2002:a92:3cd7:: with SMTP id j84mr15067873ilf.176.1583101127203; Sun, 01 Mar 2020 14:18:47 -0800 (PST) MIME-Version: 1.0 References: <20200228174630.8989-1-madhuparnabhowmik10@gmail.com> In-Reply-To: From: Joel Fernandes Date: Sun, 1 Mar 2020 17:18:36 -0500 Message-ID: Subject: Re: [PATCH 1/2] drivers: base: power: main: Use built-in RCU list checking To: "Rafael J. Wysocki" Cc: Madhuparna Bhowmik , "Rafael J. Wysocki" , Pavel Machek , Len Brown , Greg Kroah-Hartman , Linux PM , Linux Kernel Mailing List , Amol Grover , linux-kernel-mentees@lists.linuxfoundation.org, "Paul E. McKenney" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Mar 1, 2020 at 4:23 PM Rafael J. Wysocki wrote: > > On Sun, Mar 1, 2020 at 9:53 PM wrote: > > > > > > > > On March 1, 2020 3:12:53 PM EST, "Rafael J. Wysocki" wrote: > > >On Fri, Feb 28, 2020 at 6:47 PM wrote: > > >> > > >> From: Madhuparna Bhowmik > > >> > > >> This patch passes the cond argument to list_for_each_entry_rcu() > > >> to fix the following false-positive lockdep warnings: > > >> > > >> [ 330.302784] ============================= > > >> [ 330.302789] WARNING: suspicious RCU usage > > >> [ 330.302796] 5.6.0-rc1+ #5 Not tainted > > >> [ 330.302801] ----------------------------- > > >> [ 330.302808] drivers/base/power/main.c:326 RCU-list traversed in > > >non-reader section!! > > >> > > >> [ 330.303303] ============================= > > >> [ 330.303307] WARNING: suspicious RCU usage > > >> [ 330.303311] 5.6.0-rc1+ #5 Not tainted > > >> [ 330.303315] ----------------------------- > > >> [ 330.303319] drivers/base/power/main.c:1698 RCU-list traversed in > > >non-reader section!! > > >> > > >> [ 331.934969] ============================= > > >> [ 331.934971] WARNING: suspicious RCU usage > > >> [ 331.934973] 5.6.0-rc1+ #5 Not tainted > > >> [ 331.934975] ----------------------------- > > >> [ 331.934977] drivers/base/power/main.c:1238 RCU-list traversed in > > >non-reader section!! > > >> > > >> [ 332.467772] WARNING: suspicious RCU usage > > >> [ 332.467775] 5.6.0-rc1+ #5 Not tainted > > >> [ 332.467775] ----------------------------- > > >> [ 332.467778] drivers/base/power/main.c:269 RCU-list traversed in > > >non-reader section!! > > > > > >I don't see these warnings in the kernels run locally here. > > > > > >What do you do to get them? > > > > > >Joel, any comments here? > > > > You have to enable lockdep in your config. Does your setup have that? > > CONFIG_LOCK_DEBUGGING_SUPPORT=y > CONFIG_PROVE_LOCKING=y > CONFIG_DEBUG_SPINLOCK=y > CONFIG_DEBUG_LOCK_ALLOC=y > CONFIG_LOCKDEP=y This should be it. I am not sure what else Madhuparna did to trigger it. Madhuparna, could you elaborate? thanks, - Joel