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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 B2ED8C433DF for ; Wed, 19 Aug 2020 10:13:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E3B2206B5 for ; Wed, 19 Aug 2020 10:13:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Px2voPJM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728008AbgHSKNH (ORCPT ); Wed, 19 Aug 2020 06:13:07 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:31612 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727901AbgHSKMc (ORCPT ); Wed, 19 Aug 2020 06:12:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597831951; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DXpQgXtPCtA3XAl6RXZ6J9mfBUjPvtMXLXOf7p6EKhA=; b=Px2voPJMmowHpSrGXuk1FIvJlcBC3lp1NpVqRM7GSSA7WWawSvUuAgDSXNgknQJokfr7yf oNnObFjNOIKXKr2pGWomczfBEFm06A7NgorCmJc+yKU4icKytcq4BCtf6oftiVMZv47+bp 0PhFEhwNgEyH7zKwM+A+T7IHigtLnnE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-35-WGkPFn9LPGGV5gDWBEYP-Q-1; Wed, 19 Aug 2020 06:12:27 -0400 X-MC-Unique: WGkPFn9LPGGV5gDWBEYP-Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 37C1110066FB; Wed, 19 Aug 2020 10:12:26 +0000 (UTC) Received: from t480s.redhat.com (ovpn-114-11.ams2.redhat.com [10.36.114.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6081A2639D; Wed, 19 Aug 2020 10:12:24 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, David Hildenbrand , Andrew Morton , Michal Hocko , Wei Yang , Baoquan He , Pankaj Gupta , Oscar Salvador Subject: [PATCH v1 08/11] mm/memory_hotplug: simplify page onlining Date: Wed, 19 Aug 2020 12:11:54 +0200 Message-Id: <20200819101157.12723-9-david@redhat.com> In-Reply-To: <20200819101157.12723-1-david@redhat.com> References: <20200819101157.12723-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Cc: Andrew Morton Cc: Michal Hocko Cc: Wei Yang Cc: Baoquan He Cc: Pankaj Gupta Cc: Oscar Salvador Signed-off-by: David Hildenbrand --- mm/memory_hotplug.c | 38 ++++++++++---------------------------- 1 file changed, 10 insertions(+), 28 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0011a1115381c..3aba0d956f9b1 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -617,31 +617,22 @@ void generic_online_page(struct page *page, unsigned int order) } 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 */ @@ -795,7 +786,6 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type, int nid) { unsigned long flags; - unsigned long onlined_pages = 0; struct zone *zone; int need_zonelists_rebuild = 0; int ret; @@ -831,19 +821,11 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, 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); /* -- 2.26.2