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=-8.4 required=3.0 tests=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 20D64C2D0B1 for ; Tue, 4 Feb 2020 14:25:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DB24120730 for ; Tue, 4 Feb 2020 14:25:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="c3z7W9fl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB24120730 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 91A3F6B0010; Tue, 4 Feb 2020 09:25:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8A5816B0266; Tue, 4 Feb 2020 09:25:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7BBEE6B0269; Tue, 4 Feb 2020 09:25:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0186.hostedemail.com [216.40.44.186]) by kanga.kvack.org (Postfix) with ESMTP id 5C2806B0010 for ; Tue, 4 Feb 2020 09:25:28 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 1217533CD for ; Tue, 4 Feb 2020 14:25:28 +0000 (UTC) X-FDA: 76452667536.05.brake06_2fb327203b339 X-HE-Tag: brake06_2fb327203b339 X-Filterd-Recvd-Size: 5009 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Tue, 4 Feb 2020 14:25:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580826327; 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=ut05QA9J5WKSRE8iQ2AH3oPYzXnHzXfW9BoUs/aT13g=; b=c3z7W9flyFddKlyVmMluuCNT5S/u5TlsjcpbfE0Hbh81XBCFSZMKYUEKPVcBgJcAe9bVQe d493F0qrV53Irth3yNQLnmVr4ilxdthhK3ZnYk2eQpBya1QCevv75BkMlKpJztB8HmuSka M2xGt5DOXEBe3T9haPil6aNGmBiucF4= 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-172-0pa_ZXTfPAGteHs5vWnWkg-1; Tue, 04 Feb 2020 09:25:25 -0500 X-MC-Unique: 0pa_ZXTfPAGteHs5vWnWkg-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 F08C18010E6; Tue, 4 Feb 2020 14:25:22 +0000 (UTC) Received: from localhost (ovpn-13-129.pek2.redhat.com [10.72.13.129]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0DC6085785; Tue, 4 Feb 2020 14:25:19 +0000 (UTC) Date: Tue, 4 Feb 2020 22:25:16 +0800 From: Baoquan He To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, x86@kernel.org, Andrew Morton , Oscar Salvador , Michal Hocko , Pavel Tatashin , Dan Williams , Wei Yang Subject: Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span() Message-ID: <20200204142516.GD26758@MiWiFi-R3L-srv> References: <20191006085646.5768-1-david@redhat.com> <20191006085646.5768-9-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191006085646.5768-9-david@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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 10/06/19 at 10:56am, David Hildenbrand wrote: > If we have holes, the holes will automatically get detected and removed > once we remove the next bigger/smaller section. The extra checks can > go. > > Cc: Andrew Morton > Cc: Oscar Salvador > Cc: Michal Hocko > Cc: David Hildenbrand > Cc: Pavel Tatashin > Cc: Dan Williams > Cc: Wei Yang > Signed-off-by: David Hildenbrand > --- > mm/memory_hotplug.c | 34 +++++++--------------------------- > 1 file changed, 7 insertions(+), 27 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index f294918f7211..8dafa1ba8d9f 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > if (pfn) { > zone->zone_start_pfn = pfn; > zone->spanned_pages = zone_end_pfn - pfn; > + } else { > + zone->zone_start_pfn = 0; > + zone->spanned_pages = 0; > } > } else if (zone_end_pfn == end_pfn) { > /* > @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > start_pfn); > if (pfn) > zone->spanned_pages = pfn - zone_start_pfn + 1; > + else { > + zone->zone_start_pfn = 0; > + zone->spanned_pages = 0; Thinking in which case (zone_start_pfn != start_pfn) and it comes here. > + } > } > - > - /* > - * The section is not biggest or smallest mem_section in the zone, it > - * only creates a hole in the zone. So in this case, we need not > - * change the zone. But perhaps, the zone has only hole data. Thus > - * it check the zone has only hole or not. > - */ > - pfn = zone_start_pfn; > - for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { > - if (unlikely(!pfn_to_online_page(pfn))) > - continue; > - > - if (page_zone(pfn_to_page(pfn)) != zone) > - continue; > - > - /* Skip range to be removed */ > - if (pfn >= start_pfn && pfn < end_pfn) > - continue; > - > - /* If we find valid section, we have nothing to do */ > - zone_span_writeunlock(zone); > - return; > - } > - > - /* The zone has no valid section */ > - zone->zone_start_pfn = 0; > - zone->spanned_pages = 0; > zone_span_writeunlock(zone); > } > > -- > 2.21.0 > >