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=-11.6 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,USER_AGENT_SANE_1 autolearn=unavailable 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 9AC64C433E3 for ; Tue, 28 Jul 2020 13:48:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5F4B3206D7 for ; Tue, 28 Jul 2020 13:48:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XIP6Iqmh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F4B3206D7 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 CAA208D0003; Tue, 28 Jul 2020 09:48:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C5B396B005A; Tue, 28 Jul 2020 09:48:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B98928D0003; Tue, 28 Jul 2020 09:48:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0084.hostedemail.com [216.40.44.84]) by kanga.kvack.org (Postfix) with ESMTP id A5DCC6B0037 for ; Tue, 28 Jul 2020 09:48:47 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 6A1D1824805A for ; Tue, 28 Jul 2020 13:48:47 +0000 (UTC) X-FDA: 77087615094.07.fifth23_30175f026f6a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 364851803F9A7 for ; Tue, 28 Jul 2020 13:48:47 +0000 (UTC) X-HE-Tag: fifth23_30175f026f6a X-Filterd-Recvd-Size: 5194 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Tue, 28 Jul 2020 13:48:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595944126; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=X8WvcTzlaZOUusoNr92B8iYPaRM3BXRIbJcPYBAC7jk=; b=XIP6IqmhzvNj4/siiFs97Y0WRtWlFD8Z4wOQeK6W2Etw9Bedg1LR6SXhX00uYkbRSSRezW BZrR4sRQDMyzXqRUMRftkmj44O/vYwonKU/CfO8vCAPLUOaKYNIoTCmJ4OKCnswY+vNqwu qGm73SK2YYuV7Rzbwohg983MRXRqtcc= 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-120-GSqdVu7yP1iAC4jVWkZ1Jw-1; Tue, 28 Jul 2020 09:48:41 -0400 X-MC-Unique: GSqdVu7yP1iAC4jVWkZ1Jw-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 B061879EC1; Tue, 28 Jul 2020 13:48:40 +0000 (UTC) Received: from localhost (ovpn-12-117.pek2.redhat.com [10.72.12.117]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5BCFF712FA; Tue, 28 Jul 2020 13:48:31 +0000 (UTC) Date: Tue, 28 Jul 2020 21:48:26 +0800 From: Baoquan He To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mm@kvack.org, Andrew Morton , Michal Hocko , "Michael S . Tsirkin" Subject: Re: [PATCH v1 1/6] mm/page_alloc: tweak comments in has_unmovable_pages() Message-ID: <20200728134826.GC14854@MiWiFi-R3L-srv> References: <20200630142639.22770-1-david@redhat.com> <20200630142639.22770-2-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200630142639.22770-2-david@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Rspamd-Queue-Id: 364851803F9A7 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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: On 06/30/20 at 04:26pm, David Hildenbrand wrote: > Let's move the split comment regarding bootmem allocations and memory > holes, especially in the context of ZONE_MOVABLE, to the PageReserved() > check. > > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Michael S. Tsirkin > 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 48eb0f1410d47..bd3ebf08f09b9 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 "movable_core". ~~~~ should be 'movablecore', we don't have kernel parameter 'movable_core'. Otherwise, this looks good to me. Esp the code comment at below had been added very long time ago and obsolete. Reviewed-by: Baoquan He By the way, David, do you know what is the situation of having unmovable allocations inside ZONE_MOVABLE when specifying 'movablecore'? I quickly went through find_zone_movable_pfns_for_nodes(), but didn't get why. Could you tell a little more detail about it? Thanks Baoquan > + */ > 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 > >