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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,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 C843DC46470 for ; Tue, 7 Aug 2018 14:59:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EF132174C for ; Tue, 7 Aug 2018 14:59:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8EF132174C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389803AbeHGRNt (ORCPT ); Tue, 7 Aug 2018 13:13:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:60066 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2389481AbeHGRNs (ORCPT ); Tue, 7 Aug 2018 13:13:48 -0400 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 9AEEBAE04; Tue, 7 Aug 2018 14:59:03 +0000 (UTC) Date: Tue, 7 Aug 2018 16:59:00 +0200 From: Michal Hocko To: Jerome Glisse Cc: osalvador@techadventures.net, akpm@linux-foundation.org, dan.j.williams@intel.com, pasha.tatashin@oracle.com, david@redhat.com, yasu.isimatu@gmail.com, logang@deltatee.com, dave.jiang@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador Subject: Re: [RFC PATCH 2/3] mm/memory_hotplug: Create __shrink_pages and move it to offline_pages Message-ID: <20180807145900.GH10003@dhcp22.suse.cz> References: <20180807133757.18352-1-osalvador@techadventures.net> <20180807133757.18352-3-osalvador@techadventures.net> <20180807135221.GA3301@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180807135221.GA3301@redhat.com> 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 Tue 07-08-18 09:52:21, Jerome Glisse wrote: > On Tue, Aug 07, 2018 at 03:37:56PM +0200, osalvador@techadventures.net wrote: > > From: Oscar Salvador > > [...] > > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > > index 9bd629944c91..e33555651e46 100644 > > --- a/mm/memory_hotplug.c > > +++ b/mm/memory_hotplug.c > > [...] > > > /** > > * __remove_pages() - remove sections of pages from a zone > > - * @zone: zone from which pages need to be removed > > + * @nid: node which pages belong to > > * @phys_start_pfn: starting pageframe (must be aligned to start of a section) > > * @nr_pages: number of pages to remove (must be multiple of section size) > > * @altmap: alternative device page map or %NULL if default memmap is used > > @@ -548,7 +557,7 @@ static int __remove_section(struct zone *zone, struct mem_section *ms, > > * sure that pages are marked reserved and zones are adjust properly by > > * calling offline_pages(). > > */ > > -int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, > > +int __remove_pages(int nid, unsigned long phys_start_pfn, > > unsigned long nr_pages, struct vmem_altmap *altmap) > > { > > unsigned long i; > > @@ -556,10 +565,9 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, > > int sections_to_remove, ret = 0; > > > > /* In the ZONE_DEVICE case device driver owns the memory region */ > > - if (is_dev_zone(zone)) { > > - if (altmap) > > - map_offset = vmem_altmap_offset(altmap); > > - } else { > > + if (altmap) > > + map_offset = vmem_altmap_offset(altmap); > > + else { > > This will break ZONE_DEVICE at least for HMM. While i think that > altmap -> ZONE_DEVICE (ie altmap imply ZONE_DEVICE) the reverse > is not true ie ZONE_DEVICE does not necessarily imply altmap. So > with the above changes you change the expected behavior. Could you be more specific what is the expected behavior here? Is this about calling release_mem_region_adjustable? Why does is it not suitable for zone device ranges? -- Michal Hocko SUSE Labs