From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 591D140BE4; Mon, 19 Feb 2024 16:19:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708359584; cv=none; b=h4Pl7sVUNH6harYUSdGXUDYU9VRUt/mzVrOrNWPXpqnX7jxK0It/4YpwfiHcj7eMJPG54/dPGbSwKKoNcTLs/DjH7uY+KDaCHcw1EWkLmnkk6yJm7W0vOWjU/yOf4lkEcZyPTmKK5pzR8v5UjV8HMtTGg5Z7jrN+eDfPPZRNM30= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708359584; c=relaxed/simple; bh=geMTJ9lOTTXbNkYKZFBhsIQdmz8LDBCNbCre8M8nqR0=; h=From:To:Cc:Subject:References:Date:In-Reply-To:Message-ID: MIME-Version:Content-Type; b=OnisBO6ozDisvQX3znNgeJsLqLm47XXixPrKrEsq9TOTqQAOnYsnOEptiPgm47o90KH1XOiPp0lrX6YZyGo4K7Mm6WDBa6rKPhHeMQO42jofe7apZf09uC4cXapUIe1s5B5zQbiLxb7K4tbNfdTlczr+N3bezepj+9qjTGHcMXc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Xo5yyCr1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Xo5yyCr1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89F60C43399; Mon, 19 Feb 2024 16:19:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708359583; bh=geMTJ9lOTTXbNkYKZFBhsIQdmz8LDBCNbCre8M8nqR0=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=Xo5yyCr17Zoe09ZxqrdyCQU2C6g1HE9oPU0CRmvyA8NN9MqCk+sP6YsTrqD1nbheD ZGbriuY5QIQt7FJmgODmak9gdO89i6WdJuNuzt3kQS+GT5wyRNVMNWBcfHM6WuZkhR CHd6SYp3jxQa9G3TZsPxRBuOLfrRjKvdZrIcEojizE2trJ7IiUa4J1fbHERsmRcdCZ gKVmYrLRZ70GMdsr3IolfJuSY6alj3rdMbIBOn1p+WBUn2rxp0kHf2+7CQA9Hj9kg5 MbGnhP3Utq9Ok/JWLZBeqrY9Med7mcC//cLqVzvK6AkHoifC6oqHaHvL9D1lEJeiYK 80AmKKiI7eN3Q== From: Kalle Valo To: Alexis =?utf-8?Q?Lothor=C3=A9?= Cc: linux-wireless@vger.kernel.org, Ajay Singh , Claudiu Beznea , Thomas Petazzoni , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/4] wifi: wilc1000: fix RCU usage References: <20240215-wilc_fix_rcu_usage-v1-0-f610e46c6f82@bootlin.com> Date: Mon, 19 Feb 2024 18:19:40 +0200 In-Reply-To: <20240215-wilc_fix_rcu_usage-v1-0-f610e46c6f82@bootlin.com> ("Alexis =?utf-8?Q?Lothor=C3=A9=22's?= message of "Thu, 15 Feb 2024 16:36:17 +0100") Message-ID: <87h6i4mnoj.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Alexis Lothor=C3=A9 writes: > This small series aims to fix multiple warnings observed when enabling > CONFIG_PROVE_RCU_LIST: > - add missing locks to create corresponding critical read sections > - fix mix between RCU and SRCU API usage > > While at it, since SRCU API is already in use in the driver, any fix done > on RCU usage was also done with the SRCU variant of RCU API. I do not > really get why we are using SRCU in this driver instead of classic RCU, as > it seems to be done in any other wireless driver. And even more so, no other driver in drivers/net use SRCU. > My understanding is that primary SRCU use case is for compatibility > with realtime kernel, which needs to be preemptible everywhere. Has > the driver been really developped with this constraint in mind ? If > you have more details about this, feel free to educate me. Alexis, if you have the time I recommend submitting a patchset converting wilc1000 to use classic RCU. At least I have a hard time understanding why SRCU is needed, especially after seeing the warning you found. --=20 https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatc= hes