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=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 E9314C4727E for ; Mon, 28 Sep 2020 18:21:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 753862075A for ; Mon, 28 Sep 2020 18:21:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Gt3zqsfu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 753862075A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C9046B0092; Mon, 28 Sep 2020 14:21:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 052546B0093; Mon, 28 Sep 2020 14:21:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E5D6B6B0095; Mon, 28 Sep 2020 14:21:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0090.hostedemail.com [216.40.44.90]) by kanga.kvack.org (Postfix) with ESMTP id D0B6E6B0092 for ; Mon, 28 Sep 2020 14:21:45 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 92FDE8249980 for ; Mon, 28 Sep 2020 18:21:45 +0000 (UTC) X-FDA: 77313288570.30.star89_4f030ba27183 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id 67F18180B3C83 for ; Mon, 28 Sep 2020 18:21:45 +0000 (UTC) X-HE-Tag: star89_4f030ba27183 X-Filterd-Recvd-Size: 8786 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Mon, 28 Sep 2020 18:21:44 +0000 (UTC) Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601317304; 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=a/QBjOJOnjKSQGTcFwa/HDPL1lh7ZnPAc8cUq7Eyqoc=; b=Gt3zqsfuogmretKs6lL4XrRfznTuBrrr7Irn4OfHI0n9FY1fqdfd/qWBUKRpQ9QLoP6JXP 3bE/tbNEJtlHzunjc94IrXxjnBEGOQFoXbtFof2VC3w9A+gb6HGJLHFfp3ad7uYw2Ixrhl 7kB9krpmOK991ijkBC7dkOOuO3gzQ4k= 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-185-zHBegtK0MmqPunN9wGjOLg-1; Mon, 28 Sep 2020 14:21:42 -0400 X-MC-Unique: zHBegtK0MmqPunN9wGjOLg-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 1DDAF80EF8B; Mon, 28 Sep 2020 18:21:39 +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 66D2C27CC4; Mon, 28 Sep 2020 18:21:31 +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 , Vlastimil Babka , Oscar Salvador , Alexander Duyck , Mel Gorman , Michal Hocko , Dave Hansen , Wei Yang , Mike Rapoport , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu Subject: [PATCH v1 4/5] mm/page_alloc: place pages to tail in __free_pages_core() Date: Mon, 28 Sep 2020 20:21:09 +0200 Message-Id: <20200928182110.7050-5-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 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: __free_pages_core() is used when exposing fresh memory to the buddy during system boot and when onlining memory in generic_online_page(). generic_online_page() is used in two cases: 1. Direct memory onlining in online_pages(). 2. Deferred memory onlining in memory-ballooning-like mechanisms (HyperV balloon and virtio-mem), when parts of a section are kept fake-offline to be fake-onlined later on. In 1, we already place pages to the tail of the freelist. Pages will be freed to MIGRATE_ISOLATE lists first and moved to the tail of the freelis= ts via undo_isolate_page_range(). In 2, we currently don't implement a proper rule. In case of virtio-mem, where we currently always online MAX_ORDER - 1 pages, the pages will be placed to the HEAD of the freelist - undesireable. While the hyper-v balloon calls generic_online_page() with single pages, usually it will call it on successive single pages in a larger block. The pages are fresh, so place them to the tail of the freelists and avoid the PCP. In __free_pages_core(), remove the now superflouos call to set_page_refcounted() and add a comment regarding page initialization and the refcount. Note: In 2. we currently don't shuffle. If ever relevant (page shuffling is usually of limited use in virtualized environments), we might want to shuffle after a sequence of generic_online_page() calls in the relevant callers. Reviewed-by: Vlastimil Babka 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: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: Wei Liu Signed-off-by: David Hildenbrand --- mm/page_alloc.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d5a5f528b8ca..8a2134fe9947 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -270,7 +270,8 @@ bool pm_suspended_storage(void) unsigned int pageblock_order __read_mostly; #endif =20 -static void __free_pages_ok(struct page *page, unsigned int order); +static void __free_pages_ok(struct page *page, unsigned int order, + fop_t fop_flags); =20 /* * results with 256, 32 in the lowmem_reserve sysctl: @@ -682,7 +683,7 @@ static void bad_page(struct page *page, const char *r= eason) void free_compound_page(struct page *page) { mem_cgroup_uncharge(page); - __free_pages_ok(page, compound_order(page)); + __free_pages_ok(page, compound_order(page), FOP_NONE); } =20 void prep_compound_page(struct page *page, unsigned int order) @@ -1419,17 +1420,15 @@ static void free_pcppages_bulk(struct zone *zone,= int count, spin_unlock(&zone->lock); } =20 -static void free_one_page(struct zone *zone, - struct page *page, unsigned long pfn, - unsigned int order, - int migratetype) +static void free_one_page(struct zone *zone, struct page *page, unsigned= long pfn, + unsigned int order, int migratetype, fop_t fop_flags) { spin_lock(&zone->lock); if (unlikely(has_isolate_pageblock(zone) || is_migrate_isolate(migratetype))) { migratetype =3D get_pfnblock_migratetype(page, pfn); } - __free_one_page(page, pfn, zone, order, migratetype, FOP_NONE); + __free_one_page(page, pfn, zone, order, migratetype, fop_flags); spin_unlock(&zone->lock); } =20 @@ -1507,7 +1506,8 @@ void __meminit reserve_bootmem_region(phys_addr_t s= tart, phys_addr_t end) } } =20 -static void __free_pages_ok(struct page *page, unsigned int order) +static void __free_pages_ok(struct page *page, unsigned int order, + fop_t fop_flags) { unsigned long flags; int migratetype; @@ -1519,7 +1519,8 @@ static void __free_pages_ok(struct page *page, unsi= gned int order) migratetype =3D get_pfnblock_migratetype(page, pfn); local_irq_save(flags); __count_vm_events(PGFREE, 1 << order); - free_one_page(page_zone(page), page, pfn, order, migratetype); + free_one_page(page_zone(page), page, pfn, order, migratetype, + fop_flags); local_irq_restore(flags); } =20 @@ -1529,6 +1530,11 @@ void __free_pages_core(struct page *page, unsigned= int order) struct page *p =3D page; unsigned int loop; =20 + /* + * When initializing the memmap, init_single_page() sets the refcount + * of all pages to 1 ("allocated"/"not free"). We have to set the + * refcount of all involved pages to 0. + */ prefetchw(p); for (loop =3D 0; loop < (nr_pages - 1); loop++, p++) { prefetchw(p + 1); @@ -1539,8 +1545,12 @@ void __free_pages_core(struct page *page, unsigned= int order) set_page_count(p, 0); =20 atomic_long_add(nr_pages, &page_zone(page)->managed_pages); - set_page_refcounted(page); - __free_pages(page, order); + + /* + * Bypass PCP and place fresh pages right to the tail, primarily + * relevant for memory onlining. + */ + __free_pages_ok(page, order, FOP_TO_TAIL); } =20 #ifdef CONFIG_NEED_MULTIPLE_NODES @@ -3171,7 +3181,8 @@ static void free_unref_page_commit(struct page *pag= e, unsigned long pfn) */ if (migratetype >=3D MIGRATE_PCPTYPES) { if (unlikely(is_migrate_isolate(migratetype))) { - free_one_page(zone, page, pfn, 0, migratetype); + free_one_page(zone, page, pfn, 0, migratetype, + FOP_NONE); return; } migratetype =3D MIGRATE_MOVABLE; @@ -5063,7 +5074,7 @@ static inline void free_the_page(struct page *page,= unsigned int order) if (order =3D=3D 0) /* Via pcp? */ free_unref_page(page); else - __free_pages_ok(page, order); + __free_pages_ok(page, order, FOP_NONE); } =20 void __free_pages(struct page *page, unsigned int order) --=20 2.26.2