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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5CBF5C4332F for ; Mon, 12 Dec 2022 14:15:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=wqHWXZ3aH2GE/GCessRGZltvGxbeAch8EEXCUdZTwNI=; b=MeSOiYTLF65Bev eaEfNmqtoJHVRkfxDqRdZwWDu7JWjT17Nbm/O4EIEyShuRotYWLj/FhGoiqOF9jJVPJKED/9p3WHR yFCYWjB3AnhRbGTeWALtIOqxLHxm7uE1K249BxC4o6ozkhFF8EQjQZD15y/QSlgSpxq4yRpG6s/98 N7W09ZsFYhU9+t5x/GBqB9OMxCRztbF9gFkxXp3yUdUYN2y+lFPeWtUt3cdOLWr/AYkAXolOy7Npy BRfKvEr0bBZICsjyGz7hM+6RNI68mHnPFY+cXUvP/VSO1hBpnb6pa53ot352Cyvlw1OC1LPVxS25C DEywcdSnSPY6t659kx6w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p4jZx-00H7op-JV; Mon, 12 Dec 2022 14:14:49 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p4jZu-00H7Vj-PU for linux-arm-kernel@lists.infradead.org; Mon, 12 Dec 2022 14:14:48 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1670854474; 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=3VulB7zwTi0kemDdT1n64bpcErOOyRtll4L59c0fe90=; b=Kn2lcmYIxBVg4IIOPGSEGR/k1rxrXoI40fjq0Mi2Af8Pp1ZBkKGS0qXDP7lb+ypjzICgjp BEMtPaWgChGoZ89Aba7lMQePQSt0WnUDc8IvQiH/AD1K5sfCdM8L/Eol5/B8QnLgWSJvoj /xW6F9PbvVWykvvmZyQodCP/6fvIesyCPlLxNJ/SVDsdLThZSC2nawycWD64o6eZeovNAe lhEe6qcaPh+wsW8YvD2sTbHCqDoruRb2gGeWCbbwiNaF0geQ46HlVlp6frMAXKekQrsMlV lqWx7Bmj/vI4+mnvODASw7w2fHApB3XlXEhaj1ysKhU1AYeYwh8gPYeY69Hxog== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1670854474; 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=3VulB7zwTi0kemDdT1n64bpcErOOyRtll4L59c0fe90=; b=pEiYiypPCSz/2tWa+00h65aYJ3NOBXSMcRJNGIJf+cG2fJEbCiT5v7b6ioGMLLPiFzt3cH b7EAqQqwqlCyFzAg== To: Johan Hovold , Marc Zyngier Cc: x86@kernel.org, platform-driver-x86@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: Re: [PATCH v3 19/19] irqdomain: Switch to per-domain locking In-Reply-To: <20221209140150.1453-20-johan+linaro@kernel.org> References: <20221209140150.1453-1-johan+linaro@kernel.org> <20221209140150.1453-20-johan+linaro@kernel.org> Date: Mon, 12 Dec 2022 15:14:34 +0100 Message-ID: <87mt7sbtf9.ffs@tglx> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221212_061446_975726_54935ECB X-CRM114-Status: GOOD ( 10.24 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Dec 09 2022 at 15:01, Johan Hovold wrote: > The IRQ domain structures are currently protected by the global > irq_domain_mutex. Switch to using more fine-grained per-domain locking, > which may potentially speed up parallel probing somewhat. > > Note that the domain lock of the root domain (innermost domain) must be > used for hierarchical domains. For non-hierarchical domain (as for root > domains), the new root pointer is set to the domain itself so that > domain->root->mutex can be used in shared code paths. > > Also note that hierarchical domains should be constructed using > irq_domain_create_hierarchy() (or irq_domain_add_hierarchy()) to avoid > poking at irqdomain internals. While I agree in principle, this change really makes me nervous. Any fail in setting up domain->root correctly, e.g. by not using irq_domain_create_hierarchy(), cannot be detected and creates nasty to debug race conditions. So we need some debug mechanism which allows to validate that domain->root is set up correctly when domain->parent != NULL. Thanks, tglx _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel