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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 0B99FC2D0E4 for ; Tue, 17 Nov 2020 15:40:04 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0B3AD2463D for ; Tue, 17 Nov 2020 15:40:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B3AD2463D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4Cb99r2jyszDqVQ for ; Wed, 18 Nov 2020 02:40:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=suse.de (client-ip=195.135.220.15; helo=mx2.suse.de; envelope-from=osalvador@suse.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.de Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Cb97V5fQJzDqQT for ; Wed, 18 Nov 2020 02:37:58 +1100 (AEDT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 5CF0FAC23; Tue, 17 Nov 2020 15:37:53 +0000 (UTC) Date: Tue, 17 Nov 2020 16:37:50 +0100 From: Oscar Salvador To: David Hildenbrand Subject: Re: [PATCH v2 4/8] powerpc/mm: protect linear mapping modifications by a mutex Message-ID: <20201117153750.GD15987@linux> References: <20201111145322.15793-1-david@redhat.com> <20201111145322.15793-5-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201111145322.15793-5-david@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michal Hocko , Wei Yang , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Paul Mackerras , Rashmica Gupta , linuxppc-dev@lists.ozlabs.org, Andrew Morton , Mike Rapoport Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, Nov 11, 2020 at 03:53:18PM +0100, David Hildenbrand wrote: > @@ -144,7 +147,9 @@ void __ref arch_remove_linear_mapping(u64 start, u64 size) > start = (unsigned long)__va(start); > flush_dcache_range_chunked(start, start + size, FLUSH_CHUNK_SIZE); > > + mutex_lock(&linear_mapping_mutex); > ret = remove_section_mapping(start, start + size); > + mutex_unlock(&linear_mapping_mutex); > WARN_ON_ONCE(ret); My expertise in this area is low, so bear with me. Why we do not need to protect flush_dcache_range_chunked and vm_unmap_aliases? -- Oscar Salvador SUSE L3