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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 1AB1DC433DB for ; Wed, 20 Jan 2021 12:00:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 BADA322255 for ; Wed, 20 Jan 2021 12:00:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BADA322255 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tuQvfBpgY37i46Fcj/G3SEK4/ZFyA/KSqZEVW7ce6DI=; b=uer9xjzem3m0Fb5nVYpsy6o3D AJhDXbr8QhQJPDLrN6tTnYulbgAlk9Gy7rKMhIqMfF4d0t/+OKdKxlZA0BRcFBL5BHyF6GfoSTyGT Y+tIifL6k4jFDDZWqumLsOel7UWcmG5a57krhZhUI6Mbz4kOV/r3aFAwO6h2ddFGfMpevle9MCwL2 hcAGr0h/jMEEyvkz3yaRLJbVhckGyqBwfWCzCBEp7og/5d38B6TSHHCpC47M9/WgXs5AcBqW9d4IO cLCNcWKi5MXXlm3kJyVnAK/WJ+N6IjiXa8ZgQCXWNF2Nz2U9WDihgt76IJLLMGl/BysIqRCplH95F rqiuAcJJg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2C7x-0006n6-MB; Wed, 20 Jan 2021 11:58:21 +0000 Received: from mx2.suse.de ([195.135.220.15]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2C7v-0006mP-8m for linux-arm-kernel@lists.infradead.org; Wed, 20 Jan 2021 11:58:20 +0000 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 7B1E1AAAE; Wed, 20 Jan 2021 11:58:17 +0000 (UTC) Date: Wed, 20 Jan 2021 12:58:14 +0100 From: Oscar Salvador To: David Hildenbrand Subject: Re: [PATCH V3 1/3] mm/memory_hotplug: Prevalidate the address range being added with platform Message-ID: <20210120115814.GA7107@localhost.localdomain> References: <1610975582-12646-1-git-send-email-anshuman.khandual@arm.com> <1610975582-12646-2-git-send-email-anshuman.khandual@arm.com> <691872bb-b251-83e0-126e-afd54683c83e@redhat.com> <3d4f3b14-0715-b2b3-b015-04b8a77abfb8@arm.com> <30bbf862-06a4-bd1d-b902-61aa4183b819@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <30bbf862-06a4-bd1d-b902-61aa4183b819@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210120_065819_436962_8851A11B X-CRM114-Status: GOOD ( 23.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-s390@vger.kernel.org, Vasily Gorbik , Anshuman Khandual , catalin.marinas@arm.com, hca@linux.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, Will Deacon , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org 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 Wed, Jan 20, 2021 at 11:41:53AM +0100, David Hildenbrand wrote: > On 20.01.21 09:33, Anshuman Khandual wrote: > > > > > > On 1/19/21 5:51 PM, David Hildenbrand wrote: > >> On 18.01.21 14:12, Anshuman Khandual wrote: > >>> This introduces memhp_range_allowed() which can be called in various memory > >>> hotplug paths to prevalidate the address range which is being added, with > >>> the platform. Then memhp_range_allowed() calls memhp_get_pluggable_range() > >>> which provides applicable address range depending on whether linear mapping > >>> is required or not. For ranges that require linear mapping, it calls a new > >>> arch callback arch_get_mappable_range() which the platform can override. So > >>> the new callback, in turn provides the platform an opportunity to configure > >>> acceptable memory hotplug address ranges in case there are constraints. > >>> > >>> This mechanism will help prevent platform specific errors deep down during > >>> hotplug calls. This drops now redundant check_hotplug_memory_addressable() > >>> check in __add_pages() but instead adds a VM_BUG_ON() check which would > >> > >> In this patch, you keep the __add_pages() checks. But as discussed, we > >> could perform it in mm/memremap.c:pagemap_range() insted and convert it > >> to a VM_BUG_ON(). > > > > Just to be sure, will the following change achieve what you are > > suggesting here. pagemap_range() after this change, will again > > be the same like the V1 series. > > Yeah, as we used to have in v1. Maybe other reviewers (@Oscar?) have a > different opinion. No, I think that placing the check in pagemap_range() out of the if-else makes much more sense. Actually, unless my memory fails me that is what I suggested in v2. I plan to have a look at the series later this week as I am fairly busy atm. Thanks -- Oscar Salvador SUSE L3 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel