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=-7.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no 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 5A5AFC433FE for ; Thu, 3 Dec 2020 20:58:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 960EB22224 for ; Thu, 3 Dec 2020 20:58:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 960EB22224 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C0E5B6B005C; Thu, 3 Dec 2020 15:58:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BCC4F6B006C; Thu, 3 Dec 2020 15:58:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD1CF6B0068; Thu, 3 Dec 2020 15:58:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0067.hostedemail.com [216.40.44.67]) by kanga.kvack.org (Postfix) with ESMTP id 936F66B0036 for ; Thu, 3 Dec 2020 15:58:26 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 5C0E11F10 for ; Thu, 3 Dec 2020 20:58:26 +0000 (UTC) X-FDA: 77553184212.23.verse50_2c17bb3273be Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 3EB6837606 for ; Thu, 3 Dec 2020 20:58:26 +0000 (UTC) X-HE-Tag: verse50_2c17bb3273be X-Filterd-Recvd-Size: 5204 Received: from userp2130.oracle.com (userp2130.oracle.com [156.151.31.86]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Dec 2020 20:58:25 +0000 (UTC) Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B3Kra8E056480; Thu, 3 Dec 2020 20:58:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : in-reply-to : references : date : message-id : mime-version : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=PFh+aqho4pFMo2uLVRtEaPpq+r/Z03rDbIKphpTtlr4=; b=recM+3dR0nL9LolnyHAoZJNjw/ltRqEYSjjjdLjVhkwOID8ufQnQ+xLkLhqrtfeniq9L Do6/4Dk9lEa2VEZg3JhMu+9wBqSS2Llvr0z33MpZIiEB91Tq5CkcyojpGWei3makThzJ XyHaUO5aiU9RtBMjwUfHEEHPcez8Y5DTT/w0RqYeejh368AYhcpbwEyQgnKscGXbYtJM CvC1stU6cLriPyGTNfi64UZZecnBpmt9Rjh5D/jGR0hnQ+l6o1YY0beOQaeHZ6qVeapc QSD4q4Q2pQxZtgs637YJEI4y/l+Xlgvcyyea2xrxcrQJ9agr3OxTSY7vcQohG9ROWZcE tw== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 353dyr084g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 03 Dec 2020 20:58:23 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B3KoWeE190052; Thu, 3 Dec 2020 20:58:23 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 35404rda94-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 03 Dec 2020 20:58:22 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 0B3KwKSV018045; Thu, 3 Dec 2020 20:58:20 GMT Received: from parnassus (/98.229.125.203) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 03 Dec 2020 12:58:20 -0800 From: Daniel Jordan To: David Hildenbrand , Paul Menzel Cc: linux-mm@kvack.org, Arjan van de Ven , Feng Tang Subject: Re: Deferred Memory Init: How to bring rest of memory online after limiting it with `mem=XG`? In-Reply-To: <7692e410-886e-a1bb-4158-e02305fcd013@redhat.com> References: <808e493f-18a2-fe82-46b3-e44fe87e989c@redhat.com> <8a395c1a-764b-9d82-0a12-b1a9254f8d53@molgen.mpg.de> <7692e410-886e-a1bb-4158-e02305fcd013@redhat.com> Date: Thu, 03 Dec 2020 15:58:19 -0500 Message-ID: <87v9disj2s.fsf@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9824 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 bulkscore=0 malwarescore=0 mlxscore=0 mlxlogscore=999 phishscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012030122 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9824 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 bulkscore=0 clxscore=1011 mlxscore=0 spamscore=0 priorityscore=1501 mlxlogscore=999 suspectscore=1 lowpriorityscore=0 phishscore=0 adultscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012030122 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: David Hildenbrand writes: > On 03.12.20 13:52, Paul Menzel wrote: >> Dear David, >>=20 >>=20 >> Thank you for the quick response. >>=20 >>=20 >> Am 03.12.20 um 13:25 schrieb David Hildenbrand: >>> On 03.12.20 11:51, Paul Menzel wrote: >>=20 >>>> I am trying to reduce the startup time of Debian=E2=80=99s Linux 5.9.9= on a >>>> Intel Kaby Lake system with 32 GB of memory (TUXEDO Book BU1406 (Clevo >>>> N240BU)). >>=20 >> [=E2=80=A6] >>=20 >>> We do have deferred meminit in the kernel during boot that can >>> initialize memory in parallel. >>=20 >> Is that used automatically, or do I need to activate it somehow? > > If your kernel is compiled with > > CONFIG_DEFERRED_STRUCT_PAGE_INIT > > it should be enabled automatically. > > > config DEFERRED_STRUCT_PAGE_INIT > bool "Defer initialisation of struct pages to kthreads" > depends on SPARSEMEM > depends on !NEED_PER_CPU_KM > depends on 64BIT > select PADATA > help > Ordinarily all struct pages are initialised during early boot in a > single thread. On very large machines this can take a considerable > amount of time. If this option is set, large machines will bring up > a subset of memmap at boot and then initialise the rest in parallel. > This has a potential performance impact on tasks running early in the > lifetime of the system until these kthreads finish the > initialisation. Hello Paul, If it is enabled, what does dmesg | grep 'deferred pages' give you? And assuming you're running systemd, what does systemd-analyze show you? Thanks.