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=-2.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 0BF0DC43387 for ; Tue, 18 Dec 2018 14:22:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB34921873 for ; Tue, 18 Dec 2018 14:22:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545142963; bh=U6eYnHDP79qoRr8beUo2m7L2LIqIFCJ/Yja19MOPzuE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=riXIJVEN36B/GDESKdvUk4dYfjjC/3ILePweLKO0TWhieqOeabsbuUATSgrf2ITf3 3umQMgeERTF0/T4rgW5nLIH0Lz2WFGqVRriQWox/ZZysuS37fDic0KnCpUyGMWTSvE VyAzyoPmRreyD2L1VEnPsez6QyGkCwjaezP1XE2U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727038AbeLROWm (ORCPT ); Tue, 18 Dec 2018 09:22:42 -0500 Received: from mx2.suse.de ([195.135.220.15]:52972 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726426AbeLROWm (ORCPT ); Tue, 18 Dec 2018 09:22:42 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 55CA8B11B; Tue, 18 Dec 2018 14:22:40 +0000 (UTC) Date: Tue, 18 Dec 2018 15:22:39 +0100 From: Michal Hocko To: Andrew Morton Cc: "Aneesh Kumar K.V" , Alexey Kardashevskiy , mpe@ellerman.id.au, paulus@samba.org, David Gibson , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH V4 0/3] * mm/kvm/vfio/ppc64: Migrate compound pages out of CMA region Message-ID: <20181218142239.GL30879@dhcp22.suse.cz> References: <20181121092259.16482-1-aneesh.kumar@linux.ibm.com> <20181207151226.cb00ace433738cf550e66885@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181207151226.cb00ace433738cf550e66885@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 07-12-18 15:12:26, Andrew Morton wrote: > On Wed, 21 Nov 2018 14:52:56 +0530 "Aneesh Kumar K.V" wrote: > > > Subject: [PATCH V4 0/3] * mm/kvm/vfio/ppc64: Migrate compound pages out of CMA region > > Asterisk in title is strange? > > > ppc64 use CMA area for the allocation of guest page table (hash page table). We won't > > be able to start guest if we fail to allocate hash page table. We have observed > > hash table allocation failure because we failed to migrate pages out of CMA region > > because they were pinned. This happen when we are using VFIO. VFIO on ppc64 pins > > the entire guest RAM. If the guest RAM pages get allocated out of CMA region, we > > won't be able to migrate those pages. The pages are also pinned for the lifetime of the > > guest. > > > > Currently we support migration of non-compound pages. With THP and with the addition of > > hugetlb migration we can end up allocating compound pages from CMA region. This > > patch series add support for migrating compound pages. The first path adds the helper > > get_user_pages_cma_migrate() which pin the page making sure we migrate them out of > > CMA region before incrementing the reference count. > > Very little review activity. Perhaps Andrey and/or Michal can find the > time.. I will unlikely find some time before the end of the year. Sorry about that. -- Michal Hocko SUSE Labs