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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 01402C010A2 for ; Tue, 5 Nov 2019 10:19:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AE1262190F for ; Tue, 5 Nov 2019 10:19:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hrrgGHlA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE1262190F 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 476466B0003; Tue, 5 Nov 2019 05:19:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3FFF76B0006; Tue, 5 Nov 2019 05:19:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C8376B0007; Tue, 5 Nov 2019 05:19:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0161.hostedemail.com [216.40.44.161]) by kanga.kvack.org (Postfix) with ESMTP id 12A9B6B0003 for ; Tue, 5 Nov 2019 05:19:15 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id A49E4246A for ; Tue, 5 Nov 2019 10:19:14 +0000 (UTC) X-FDA: 76121826228.21.toad06_165d71d09ec10 X-HE-Tag: toad06_165d71d09ec10 X-Filterd-Recvd-Size: 6025 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Tue, 5 Nov 2019 10:19:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572949153; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zpJOg9tRFGLs7o7eYo++6NFqtTaXes69ojKC+HhCSpc=; b=hrrgGHlAzYGNFIJo7bxvwJJ8vTsWuRiQJ9NHG3v7Xituo+YXpRvlFSMAgw7qmq5x2jc9+z j7ilIF+abF7BhnvKUElrFD+0EbS0ZfCc2fJg89LTA9cWN0vWknBI7WhbBLN0Xwnm9/qzZM +sS4FS+B9pAvdcUtEzSZ7aMY1xuLOB8= 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-267-_Ng1Kzh9PfuCsQVariDZFQ-1; Tue, 05 Nov 2019 05:19:11 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 87B62FF; Tue, 5 Nov 2019 10:19:05 +0000 (UTC) Received: from [10.36.117.253] (ovpn-117-253.ams2.redhat.com [10.36.117.253]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB3B1608AC; Tue, 5 Nov 2019 10:18:50 +0000 (UTC) Subject: Re: [PATCH v1 09/10] mm/memory_hotplug: Don't mark pages PG_reserved when initializing the memmap To: Boris Ostrovsky , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Michal Hocko , Andrew Morton , kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-hyperv@vger.kernel.org, devel@driverdev.osuosl.org, xen-devel@lists.xenproject.org, x86@kernel.org, Alexander Duyck , Alexander Duyck , Alex Williamson , Allison Randal , Andy Lutomirski , "Aneesh Kumar K.V" , Anshuman Khandual , Anthony Yznaga , Benjamin Herrenschmidt , Borislav Petkov , Christophe Leroy , Cornelia Huck , Dan Williams , Dave Hansen , Haiyang Zhang , "H. Peter Anvin" , Ingo Molnar , "Isaac J. Manjarres" , Jim Mattson , Joerg Roedel , Johannes Weiner , Juergen Gross , KarimAllah Ahmed , Kees Cook , "K. Y. Srinivasan" , "Matthew Wilcox (Oracle)" , Matt Sickler , Mel Gorman , Michael Ellerman , Michal Hocko , Mike Rapoport , Mike Rapoport , Nicholas Piggin , Oscar Salvador , Paolo Bonzini , Paul Mackerras , Paul Mackerras , Pavel Tatashin , Pavel Tatashin , Peter Zijlstra , Qian Cai , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Sasha Levin , Sean Christopherson , Stefano Stabellini , Stephen Hemminger , Thomas Gleixner , Vitaly Kuznetsov , Vlastimil Babka , Wanpeng Li , YueHaibing References: <20191024120938.11237-1-david@redhat.com> <20191024120938.11237-10-david@redhat.com> <4b88ebd7-255d-4f02-a347-5a6c0f4f4ac4@oracle.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: Date: Tue, 5 Nov 2019 11:18:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <4b88ebd7-255d-4f02-a347-5a6c0f4f4ac4@oracle.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: _Ng1Kzh9PfuCsQVariDZFQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed 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: On 04.11.19 23:44, Boris Ostrovsky wrote: > On 10/24/19 8:09 AM, David Hildenbrand wrote: >> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c >> index 4f2e78a5e4db..af69f057913a 100644 >> --- a/drivers/xen/balloon.c >> +++ b/drivers/xen/balloon.c >> @@ -374,6 +374,13 @@ static void xen_online_page(struct page *page, unsi= gned int order) >> =09mutex_lock(&balloon_mutex); >> =09for (i =3D 0; i < size; i++) { >> =09=09p =3D pfn_to_page(start_pfn + i); >> +=09=09/* >> +=09=09 * TODO: The core used to mark the pages reserved. Most probably >> +=09=09 * we can stop doing that now. However, especially >> +=09=09 * alloc_xenballooned_pages() left PG_reserved set >> +=09=09 * on pages that can get mapped to user space. >> +=09=09 */ >> +=09=09__SetPageReserved(p); >=20 > I suspect this is not needed. Pages can get into balloon either from > here or from non-hotplug path (e.g. decrease_reservation()) and so when > we get a page from the balloon we would get a random page that may or > may not have Reserved bit set. Yeah, I also think it is fine. If you agree, I'll drop this hunk and add=20 details to the patch description. --=20 Thanks, David / dhildenb