From patchwork Mon Sep 28 18:21:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11804521 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 E71626CB for ; Mon, 28 Sep 2020 18:21:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B475D20757 for ; Mon, 28 Sep 2020 18:21:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="F+qh/i92" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726773AbgI1SVp (ORCPT ); Mon, 28 Sep 2020 14:21:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:32499 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726739AbgI1SVk (ORCPT ); Mon, 28 Sep 2020 14:21:40 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601317297; 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=6dOV1555OsoEI5HRuB+h7DxLNyiNQ9P4qHlU7ldsU34=; b=F+qh/i92be83QLCqKsvpU9061mqHF4KAPqTaL61aU5SUOmjkEqlgJKfowy0hy1fNJypzvk D+Ykr3+kP/zaprjZ3ujl1eorOwt5TkApjgjxBU3t4Ekj9OXoYZgvTT7Bz6kyDa+DgmdZEv uMqohVHIHwLnyKFm22hcxDQBRG4LtN8= 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-407-5ki3VTmDNWmGKQdsRmvziA-1; Mon, 28 Sep 2020 14:21:33 -0400 X-MC-Unique: 5ki3VTmDNWmGKQdsRmvziA-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 17765186840C; Mon, 28 Sep 2020 18:21:31 +0000 (UTC) Received: from t480s.redhat.com (ovpn-112-106.ams2.redhat.com [10.36.112.106]) by smtp.corp.redhat.com (Postfix) with ESMTP id D602A27CC7; Mon, 28 Sep 2020 18:21:27 +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 , Oscar Salvador , Alexander Duyck , Mel Gorman , Michal Hocko , Dave Hansen , Vlastimil Babka , Wei Yang , Mike Rapoport , Scott Cheloha , Michael Ellerman Subject: [PATCH v1 3/5] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate() Date: Mon, 28 Sep 2020 20:21:08 +0200 Message-Id: <20200928182110.7050-4-david@redhat.com> In-Reply-To: <20200928182110.7050-1-david@redhat.com> References: <20200928182110.7050-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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. Add a "to_tail" parameter to move_freepages_block() but introduce a a new move_to_free_list_tail() - similar to add_to_free_list_tail(). This change results in all pages getting onlined via online_pages() to be placed to the tail of the freelist. Reviewed-by: Oscar Salvador 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 Acked-by: Pankaj Gupta Reviewed-by: Wei Yang --- include/linux/page-isolation.h | 4 ++-- mm/page_alloc.c | 35 +++++++++++++++++++++++----------- mm/page_isolation.c | 12 +++++++++--- 3 files changed, 35 insertions(+), 16 deletions(-) diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h index 572458016331..3eca9b3c5305 100644 --- a/include/linux/page-isolation.h +++ b/include/linux/page-isolation.h @@ -36,8 +36,8 @@ static inline bool is_migrate_isolate(int migratetype) struct page *has_unmovable_pages(struct zone *zone, struct page *page, int migratetype, int flags); 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(struct zone *zone, struct page *page, int migratetype, + bool to_tail, int *num_movable); /* * 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 9e3ed4a6f69a..d5a5f528b8ca 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -905,6 +905,15 @@ 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) { @@ -2338,9 +2347,9 @@ static inline struct page *__rmqueue_cma_fallback(struct zone *zone, * Note that start_page and end_pages are not aligned on a pageblock * boundary. If alignment is required, use move_freepages_block() */ -static int move_freepages(struct zone *zone, - struct page *start_page, struct page *end_page, - int migratetype, int *num_movable) +static int move_freepages(struct zone *zone, struct page *start_page, + struct page *end_page, int migratetype, + bool to_tail, int *num_movable) { struct page *page; unsigned int order; @@ -2371,7 +2380,10 @@ 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; } @@ -2379,8 +2391,8 @@ 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) +int move_freepages_block(struct zone *zone, struct page *page, int migratetype, + bool to_tail, int *num_movable) { unsigned long start_pfn, end_pfn; struct page *start_page, *end_page; @@ -2401,7 +2413,7 @@ int move_freepages_block(struct zone *zone, struct page *page, return 0; return move_freepages(zone, start_page, end_page, migratetype, - num_movable); + to_tail, num_movable); } static void change_pageblock_range(struct page *pageblock_page, @@ -2526,8 +2538,8 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page, if (!whole_block) goto single_page; - free_pages = move_freepages_block(zone, page, start_type, - &movable_pages); + free_pages = move_freepages_block(zone, page, start_type, false, + &movable_pages); /* * Determine how many pages are compatible with our allocation. * For movable allocation, it's the number of movable pages which @@ -2635,7 +2647,8 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone, && !is_migrate_cma(mt)) { zone->nr_reserved_highatomic += pageblock_nr_pages; set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); - move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL); + move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, false, + NULL); } out_unlock: @@ -2711,7 +2724,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, */ set_pageblock_migratetype(page, ac->migratetype); ret = move_freepages_block(zone, page, ac->migratetype, - NULL); + false, NULL); if (ret) { spin_unlock_irqrestore(&zone->lock, flags); return ret; diff --git a/mm/page_isolation.c b/mm/page_isolation.c index abfe26ad59fd..de44e1329706 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -45,7 +45,7 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_ set_pageblock_migratetype(page, MIGRATE_ISOLATE); zone->nr_isolate_pageblock++; nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE, - NULL); + false, NULL); __mod_zone_freepage_state(zone, -nr_pages, mt); spin_unlock_irqrestore(&zone->lock, flags); @@ -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 +106,15 @@ 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 freelist. This is an optimization for memory + * onlining - just onlined memory won't immediately be considered for + * allocation. */ if (!isolated_page) { - nr_pages = move_freepages_block(zone, page, migratetype, NULL); + nr_pages = move_freepages_block(zone, page, migratetype, true, + NULL); __mod_zone_freepage_state(zone, nr_pages, migratetype); } set_pageblock_migratetype(page, migratetype);