From patchwork Wed Sep 16 18:34:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11780467 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AF8121709 for ; Wed, 16 Sep 2020 18:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 955FC221EB for ; Wed, 16 Sep 2020 18:35:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="d03AaQ08" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727958AbgIPSfz (ORCPT ); Wed, 16 Sep 2020 14:35:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:21899 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728168AbgIPSej (ORCPT ); Wed, 16 Sep 2020 14:34:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600281278; 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=0t7j7jP+qkUR+trEToGItxDCR3dDkhRdZQY/0mmtExE=; b=d03AaQ08GJF0wBzkDoTPF7l3twwfnxc+yrVWMcwCXox5qhHMjnYivQj/wBTnPbgz7kLXKO iKcCZxndRaHgiUEd4A6u5yZWocTE4Cz1PE3MaP7fsuzvNzBa5vOMe6X+3QLpRs7JNerDjS 58ylHihe7WVQ3tB+OSNp+NEYR8nUSbQ= 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-292-b6HDvSNPMlaeLBzxJvygUg-1; Wed, 16 Sep 2020 14:34:33 -0400 X-MC-Unique: b6HDvSNPMlaeLBzxJvygUg-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 78468186DD2A; Wed, 16 Sep 2020 18:34:31 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-190.ams2.redhat.com [10.36.113.190]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3FEFF19D61; Wed, 16 Sep 2020 18:34:28 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-hyperv@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, Andrew Morton , David Hildenbrand , Alexander Duyck , Mel Gorman , Michal Hocko , Dave Hansen , Vlastimil Babka , Wei Yang , Oscar Salvador , Mike Rapoport , Scott Cheloha , Michael Ellerman Subject: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate() Date: Wed, 16 Sep 2020 20:34:10 +0200 Message-Id: <20200916183411.64756-4-david@redhat.com> In-Reply-To: <20200916183411.64756-1-david@redhat.com> References: <20200916183411.64756-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Page isolation doesn't actually touch the pages, it simply isolates pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist. We already place pages to the tail of the freelists when undoing isolation via __putback_isolated_page(), let's do it in any case (e.g., if order == pageblock_order) and document the behavior. This change results in all pages getting onlined via online_pages() to be placed to the tail of the freelist. Cc: Andrew Morton Cc: Alexander Duyck Cc: Mel Gorman Cc: Michal Hocko Cc: Dave Hansen Cc: Vlastimil Babka Cc: Wei Yang Cc: Oscar Salvador Cc: Mike Rapoport Cc: Scott Cheloha Cc: Michael Ellerman Signed-off-by: David Hildenbrand Reviewed-by: Oscar Salvador --- include/linux/page-isolation.h | 2 ++ mm/page_alloc.c | 36 +++++++++++++++++++++++++++++----- mm/page_isolation.c | 8 ++++++-- 3 files changed, 39 insertions(+), 7 deletions(-) diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h index 572458016331..a36be2cf4dbb 100644 --- a/include/linux/page-isolation.h +++ b/include/linux/page-isolation.h @@ -38,6 +38,8 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page, void set_pageblock_migratetype(struct page *page, int migratetype); int move_freepages_block(struct zone *zone, struct page *page, int migratetype, int *num_movable); +int move_freepages_block_tail(struct zone *zone, struct page *page, + int migratetype); /* * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index bba9a0f60c70..75b0f49b4022 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -899,6 +899,15 @@ static inline void move_to_free_list(struct page *page, struct zone *zone, list_move(&page->lru, &area->free_list[migratetype]); } +/* Used for pages which are on another list */ +static inline void move_to_free_list_tail(struct page *page, struct zone *zone, + unsigned int order, int migratetype) +{ + struct free_area *area = &zone->free_area[order]; + + list_move_tail(&page->lru, &area->free_list[migratetype]); +} + static inline void del_page_from_free_list(struct page *page, struct zone *zone, unsigned int order) { @@ -2323,7 +2332,7 @@ static inline struct page *__rmqueue_cma_fallback(struct zone *zone, */ static int move_freepages(struct zone *zone, struct page *start_page, struct page *end_page, - int migratetype, int *num_movable) + int migratetype, int *num_movable, bool to_tail) { struct page *page; unsigned int order; @@ -2354,7 +2363,10 @@ static int move_freepages(struct zone *zone, VM_BUG_ON_PAGE(page_zone(page) != zone, page); order = page_order(page); - move_to_free_list(page, zone, order, migratetype); + if (to_tail) + move_to_free_list_tail(page, zone, order, migratetype); + else + move_to_free_list(page, zone, order, migratetype); page += 1 << order; pages_moved += 1 << order; } @@ -2362,8 +2374,9 @@ static int move_freepages(struct zone *zone, return pages_moved; } -int move_freepages_block(struct zone *zone, struct page *page, - int migratetype, int *num_movable) +static int __move_freepages_block(struct zone *zone, struct page *page, + int migratetype, int *num_movable, + bool to_tail) { unsigned long start_pfn, end_pfn; struct page *start_page, *end_page; @@ -2384,7 +2397,20 @@ int move_freepages_block(struct zone *zone, struct page *page, return 0; return move_freepages(zone, start_page, end_page, migratetype, - num_movable); + num_movable, to_tail); +} + +int move_freepages_block(struct zone *zone, struct page *page, + int migratetype, int *num_movable) +{ + return __move_freepages_block(zone, page, migratetype, num_movable, + false); +} + +int move_freepages_block_tail(struct zone *zone, struct page *page, + int migratetype) +{ + return __move_freepages_block(zone, page, migratetype, NULL, true); } static void change_pageblock_range(struct page *pageblock_page, diff --git a/mm/page_isolation.c b/mm/page_isolation.c index abfe26ad59fd..84aa1d14751d 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -83,7 +83,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype) * Because freepage with more than pageblock_order on isolated * pageblock is restricted to merge due to freepage counting problem, * it is possible that there is free buddy page. - * move_freepages_block() doesn't care of merge so we need other + * move_freepages_block*() don't care about merging, so we need another * approach in order to merge them. Isolation and free will make * these pages to be merged. */ @@ -106,9 +106,13 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype) * If we isolate freepage with more than pageblock_order, there * should be no freepage in the range, so we could avoid costly * pageblock scanning for freepage moving. + * + * We didn't actually touch any of the isolated pages, so place them + * to the tail of the freelists. This is especially relevant during + * memory onlining. */ if (!isolated_page) { - nr_pages = move_freepages_block(zone, page, migratetype, NULL); + nr_pages = move_freepages_block_tail(zone, page, migratetype); __mod_zone_freepage_state(zone, nr_pages, migratetype); } set_pageblock_migratetype(page, migratetype);