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=-10.1 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 12559C433E1 for ; Tue, 4 Aug 2020 19:42:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F297F2076E for ; Tue, 4 Aug 2020 19:42:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="W4EMywi+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728794AbgHDTmG (ORCPT ); Tue, 4 Aug 2020 15:42:06 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:37427 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728462AbgHDTmD (ORCPT ); Tue, 4 Aug 2020 15:42:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596570122; 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=94kv3iM7voNuc/GuCMOJeaJASAgCqOV3S0igLlKUpuI=; b=W4EMywi+acxZSmpkj0onaelgVicohfLwm/DSQm50tKTU3tBZhgVmt2WbXu8WKv1Y/SoFrB d3l+JiiRCdQvb9qSDHSs6FsqV7G2j0f/8OtOyFsp+G3pgvJazqLuIxNAqHquXJ122qGrrj xdy2+5ecSzGPWLg1pJRFc+k9N0yNZhA= 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-58-VlR3S6k3NKaBmdM_PavKFA-1; Tue, 04 Aug 2020 15:42:00 -0400 X-MC-Unique: VlR3S6k3NKaBmdM_PavKFA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 49D8858; Tue, 4 Aug 2020 19:41:59 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-95.ams2.redhat.com [10.36.113.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 455BD72E4F; Tue, 4 Aug 2020 19:41:57 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, linux-mm@kvack.org, David Hildenbrand , Baoquan He , Andrew Morton , Michal Hocko , "Michael S . Tsirkin" , Mike Kravetz , Pankaj Gupta Subject: [PATCH v4 2/6] mm/page_alloc: tweak comments in has_unmovable_pages() Date: Tue, 4 Aug 2020 21:41:38 +0200 Message-Id: <20200804194142.28279-3-david@redhat.com> In-Reply-To: <20200804194142.28279-1-david@redhat.com> References: <20200804194142.28279-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let's move the split comment regarding bootmem allocations and memory holes, especially in the context of ZONE_MOVABLE, to the PageReserved() check. Reviewed-by: Baoquan He Cc: Andrew Morton Cc: Michal Hocko Cc: Michael S. Tsirkin Cc: Mike Kravetz Cc: Pankaj Gupta Signed-off-by: David Hildenbrand --- mm/page_alloc.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e028b87ce2942..042ba09d70c5d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8207,14 +8207,6 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page, unsigned long iter = 0; unsigned long pfn = page_to_pfn(page); - /* - * TODO we could make this much more efficient by not checking every - * page in the range if we know all of them are in MOVABLE_ZONE and - * that the movable zone guarantees that pages are migratable but - * the later is not the case right now unfortunatelly. E.g. movablecore - * can still lead to having bootmem allocations in zone_movable. - */ - if (is_migrate_cma_page(page)) { /* * CMA allocations (alloc_contig_range) really need to mark @@ -8233,6 +8225,12 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page, page = pfn_to_page(pfn + iter); + /* + * Both, bootmem allocations and memory holes are marked + * PG_reserved and are unmovable. We can even have unmovable + * allocations inside ZONE_MOVABLE, for example when + * specifying "movablecore". + */ if (PageReserved(page)) return page; @@ -8306,14 +8304,6 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page, * it. But now, memory offline itself doesn't call * shrink_node_slabs() and it still to be fixed. */ - /* - * If the page is not RAM, page_count()should be 0. - * we don't need more check. This is an _used_ not-movable page. - * - * The problematic thing here is PG_reserved pages. PG_reserved - * is set to both of a memory hole page and a _used_ kernel - * page at boot. - */ return page; } return NULL; -- 2.26.2