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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 34ED7C43457 for ; Fri, 16 Oct 2020 03:08:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCA8F2087D for ; Fri, 16 Oct 2020 03:08:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602817694; bh=/GXdQy0i9xoqMZ6zs7xVT9rFtrrZd+wmG75JlbBpekc=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=MvJppH5lYp/+sS98V/903Nz+xHOkesIF53ETnYC5iFAVc/GmOd263xlzXPZSzp6lt jYi4vU77XGdrxHeVGTNOsfSvjBgGL9YYoXXllYOIxG/ZNR1+nIsFE8cFQc4mJlb1WW KRsoD/nYWmwlfEd+rsivhUeMuXpsm5M+qrDQAwRY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732377AbgJPDIO (ORCPT ); Thu, 15 Oct 2020 23:08:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:45926 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727382AbgJPDIO (ORCPT ); Thu, 15 Oct 2020 23:08:14 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F059820878; Fri, 16 Oct 2020 03:08:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602817692; bh=/GXdQy0i9xoqMZ6zs7xVT9rFtrrZd+wmG75JlbBpekc=; h=Date:From:To:Subject:In-Reply-To:From; b=CFpNYS+bqgvkp88B1ZqXOLauMMj+gZJafb1g/rMyZUIdSJFYcsBbR0hy8t7q6DEu6 7gI3mjkDTwHABmsgWlWY0oMM4t+3vQjf1gvaqdk5lrTd7r4lTYPWwrfpmBHjYr2g3G 4BF53lWNM8oEliDNuBMcIj9q/ayWI0OWxkVY+QzQ= Date: Thu, 15 Oct 2020 20:08:11 -0700 From: Andrew Morton To: akpm@linux-foundation.org, bhe@redhat.com, charante@codeaurora.org, dan.j.williams@intel.com, david@redhat.com, fenghua.yu@intel.com, logang@deltatee.com, mgorman@suse.de, mgorman@techsingularity.net, mhocko@suse.com, mm-commits@vger.kernel.org, osalvador@suse.de, pankaj.gupta.linux@gmail.com, richard.weiyang@linux.alibaba.com, rppt@kernel.org, tony.luck@intel.com, torvalds@linux-foundation.org, walken@google.com, willy@infradead.org Subject: [patch 065/156] mm/memory_hotplug: simplify page onlining Message-ID: <20201016030811.oB--W04MD%akpm@linux-foundation.org> In-Reply-To: <20201015194043.84cda0c1d6ca2a6847f2384a@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: David Hildenbrand Subject: mm/memory_hotplug: simplify page onlining We don't allow to offline memory with holes, all boot memory is online, and all hotplugged memory cannot have holes. We can now simplify onlining of pages. As we only allow to online/offline full sections and sections always span full MAX_ORDER_NR_PAGES, we can just process MAX_ORDER - 1 pages without further special handling. The number of onlined pages simply corresponds to the number of pages we were requested to online. While at it, refine the comment regarding the callback not exposing all pages to the buddy. Link: https://lkml.kernel.org/r/20200819175957.28465-8-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Michal Hocko Reviewed-by: Oscar Salvador Cc: Wei Yang Cc: Baoquan He Cc: Pankaj Gupta Cc: Charan Teja Reddy Cc: Dan Williams Cc: Fenghua Yu Cc: Logan Gunthorpe Cc: "Matthew Wilcox (Oracle)" Cc: Mel Gorman Cc: Mel Gorman Cc: Michel Lespinasse Cc: Mike Rapoport Cc: Tony Luck Signed-off-by: Andrew Morton --- mm/memory_hotplug.c | 38 ++++++++++---------------------------- 1 file changed, 10 insertions(+), 28 deletions(-) --- a/mm/memory_hotplug.c~mm-memory_hotplug-simplify-page-onlining +++ a/mm/memory_hotplug.c @@ -625,31 +625,22 @@ void generic_online_page(struct page *pa } EXPORT_SYMBOL_GPL(generic_online_page); -static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, - void *arg) +static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) { const unsigned long end_pfn = start_pfn + nr_pages; unsigned long pfn; - int order; /* - * Online the pages. The callback might decide to keep some pages - * PG_reserved (to add them to the buddy later), but we still account - * them as being online/belonging to this zone ("present"). + * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might + * decide to not expose all pages to the buddy (e.g., expose them + * later). We account all pages as being online and belonging to this + * zone ("present"). */ - for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) { - order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn))); - /* __free_pages_core() wants pfns to be aligned to the order */ - if (WARN_ON_ONCE(!IS_ALIGNED(pfn, 1ul << order))) - order = 0; - (*online_page_callback)(pfn_to_page(pfn), order); - } + for (pfn = start_pfn; pfn < end_pfn; pfn += MAX_ORDER_NR_PAGES) + (*online_page_callback)(pfn_to_page(pfn), MAX_ORDER - 1); /* mark all involved sections as online */ online_mem_sections(start_pfn, end_pfn); - - *(unsigned long *)arg += nr_pages; - return 0; } /* check which state of node_states will be changed when online memory */ @@ -803,7 +794,6 @@ int __ref online_pages(unsigned long pfn int online_type, int nid) { unsigned long flags; - unsigned long onlined_pages = 0; struct zone *zone; int need_zonelists_rebuild = 0; int ret; @@ -839,19 +829,11 @@ int __ref online_pages(unsigned long pfn setup_zone_pageset(zone); } - ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, - online_pages_range); - if (ret) { - /* not a single memory resource was applicable */ - if (need_zonelists_rebuild) - zone_pcp_reset(zone); - goto failed_addition; - } - - zone->present_pages += onlined_pages; + online_pages_range(pfn, nr_pages); + zone->present_pages += nr_pages; pgdat_resize_lock(zone->zone_pgdat, &flags); - zone->zone_pgdat->node_present_pages += onlined_pages; + zone->zone_pgdat->node_present_pages += nr_pages; pgdat_resize_unlock(zone->zone_pgdat, &flags); /* _