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 58779C56202 for ; Tue, 17 Nov 2020 15:37:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 035962222C for ; Tue, 17 Nov 2020 15:37:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 035962222C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1D28C6B0074; Tue, 17 Nov 2020 10:37:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 185CA6B0075; Tue, 17 Nov 2020 10:37:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 04BAF6B0078; Tue, 17 Nov 2020 10:37:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0024.hostedemail.com [216.40.44.24]) by kanga.kvack.org (Postfix) with ESMTP id CA56E6B0074 for ; Tue, 17 Nov 2020 10:37:55 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 4AB053626 for ; Tue, 17 Nov 2020 15:37:55 +0000 (UTC) X-FDA: 77494315710.15.net96_600a26e27332 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id 0529D1814B0C7 for ; Tue, 17 Nov 2020 15:37:54 +0000 (UTC) X-HE-Tag: net96_600a26e27332 X-Filterd-Recvd-Size: 1938 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Tue, 17 Nov 2020 15:37:54 +0000 (UTC) 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 Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Rashmica Gupta , Andrew Morton , Mike Rapoport , Michal Hocko , Wei Yang 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-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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