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 7D044C76199 for ; Sun, 16 Feb 2020 15:36:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 571462086A for ; Sun, 16 Feb 2020 15:36:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b="B62hACUi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728390AbgBPPf7 (ORCPT ); Sun, 16 Feb 2020 10:35:59 -0500 Received: from dvalin.narfation.org ([213.160.73.56]:58610 "EHLO dvalin.narfation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728333AbgBPPf7 (ORCPT ); Sun, 16 Feb 2020 10:35:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1581867357; 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: in-reply-to:in-reply-to:references:references; bh=ERM3RGanh1fJgg7kpnX8A1AoqKzN5Z7w2qMVfhCXT1I=; b=B62hACUiCwcx0eJVymY+ugJzprPBeXkRoSzSZAHbzM4bleKfk4DDX6TUntzaHJKanWzBnk D1HxNnRqj64HXoh1XTy5wSRdUXKwpTmMgvcCNaEqpOK8iku8iNtg6+e3jxpjxeka9e2G/H Sk6wU7zF21xY4t1PKhmMROuotTo+VII= From: Sven Eckelmann To: Madhuparna Bhowmik Cc: mareklindner@neomailbox.ch, sw@simonwunderlich.de, a@unstable.cc, davem@davemloft.net, b.a.t.m.a.n@lists.open-mesh.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, joel@joelfernandes.org, frextrite@gmail.com, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH] net: batman-adv: Use built-in RCU list checking Date: Sun, 16 Feb 2020 16:35:54 +0100 Message-ID: <1634394.jP7ydfi60B@sven-edge> In-Reply-To: <20200216153324.GA4542@madhuparna-HP-Notebook> References: <20200216144718.2841-1-madhuparnabhowmik10@gmail.com> <3655191.udZcvKk8tv@sven-edge> <20200216153324.GA4542@madhuparna-HP-Notebook> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2119546.QtC4LbVagd"; micalg="pgp-sha512"; protocol="application/pgp-signature" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --nextPart2119546.QtC4LbVagd Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" On Sunday, 16 February 2020 16:33:24 CET Madhuparna Bhowmik wrote: [...] > > Can you tell us how you've identified these four hlist_for_each_entry_rcu? > > The other hlist_for_each_entry_rcu() are used under the protection of > rcu_read_lock(). We only need to pass the cond when > hlist_for_each_entry_rcu() is used under a > different lock (not under rcu_red_lock()) because according to the current scheme a lockdep splat > is generated when hlist_for_each_entry_rcu() is used outside of > rcu_read_lock() or the lockdep condition (the cond argument) evaluates > to false. So, we need to pass this cond when it is used under the > protection of spinlock or mutex etc. and not required if rcu_read_lock() > is used. I understand this part. I was asking how you've identified them. Did you use any tool for that? coccinelle, sparse, ... Kind regards, Sven --nextPart2119546.QtC4LbVagd Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEF10rh2Elc9zjMuACXYcKB8Eme0YFAl5JYVoACgkQXYcKB8Em e0ZuPRAAmCB3qGjKpbrldhlDz7BJwE/RY7I7K2zMd0bsx9IV/WmU0fmsplSNNf9m m7LaBD/F+4BxSBvaPlE19OXOTLurtetpsL9J7/RgP67jl9SBGglvTwNUtx45PoNZ QTteXCARAK9DpzpYJzMZjeplDkJ0kH7OmTFlDypKNxFyRH+29ePII0TADeYfRo/7 B9TYrS/sT/idL15gm1KimGNbwjUpr+9KlBg6ASs2HlhhX/dI5Ah2Cpt9xZYD4FZ+ IF5AsS+s0wEln3Yycd4xyHEHUoYrP+MjF9k7MR+o7EalZD3/2LDUUPGy8akkkZ36 xOgDyfVVOWQ6Ew6r1fl5Tty4pz3Kkt7HewRsOkPUkJrX6JvxGoq+FlxEJwDv0oL7 fLsCl/A3otfLCqxGTlZaIKOJmBg1t/eeFGHx6c31yza6HxgH3X8uQ7i6RtRy7Vac FNciX8lPZjqjldm3rRpVweopBB/11v72mZRsV/L50tx1piVfQtmYvtseSXPvyTfS mQufCXGXdZ0UI6rVda9bzzO7Yi1c+I2sczMw5YA7mDrAeEWldVBT/mcJsoRTz4dh uWGnh+fUbD5GFOSnkctXZkN4BVN75ZGztTfcsDdOF9Aa+JOq6mrljeSPsAgKxuly DhbSVonE5CHUVgCD/4Mv8phrEbKRIBPbFFZjlmQ9fKz6cT+Rz/s= =AU3U -----END PGP SIGNATURE----- --nextPart2119546.QtC4LbVagd--