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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, 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 E82CEC433E0 for ; Mon, 4 Jan 2021 22:20:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE7462251F for ; Mon, 4 Jan 2021 22:20:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726671AbhADWUW (ORCPT ); Mon, 4 Jan 2021 17:20:22 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:58098 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726026AbhADWUV (ORCPT ); Mon, 4 Jan 2021 17:20:21 -0500 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 104MImkr050419; Mon, 4 Jan 2021 22:19:26 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=lIH/kquWfLYyDT0ExzrwgCA4EN7fnzgIWbeQ+9ozz0E=; b=Urk7Wz3kySADtOFVefsg+IqfDa2J2rR6pXzcaDbkIXeic2oq91KE1X5ySaOgw1FaL00/ M0jQoOoh6l5GF38sGSi+3aMw3nLQz4LPz2eok+vgEmB8SZPu2GkIdhUo++iWD89PzogR twzXFZDC6UGg0fH0h+JWefDUIUk74n4Y7IE7vWaQtPEv2Ng1wYf2luERcizsmlvF22PU /v/YfkJAm39iznEQyIcbi0xOQPiV2PcCqi91DSsL8MhPMzsmF9yfF1oXhTFBWQrouu14 yAwzPpib+W0CI15bjFwOeBNhQbvBba2fnKO/gahDu5QrkS0kCPdQlGrOo3rdK3M+Tyoc Rg== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2130.oracle.com with ESMTP id 35tebaph2n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 04 Jan 2021 22:19:26 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 104M0KWS103879; Mon, 4 Jan 2021 22:17:25 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 35uxnrsyj8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 04 Jan 2021 22:17:25 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 104MHIev011507; Mon, 4 Jan 2021 22:17:18 GMT Received: from [192.168.2.112] (/50.38.35.18) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 04 Jan 2021 14:17:18 -0800 Subject: Re: [PATCH 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one To: Muchun Song , akpm@linux-foundation.org Cc: hillf.zj@alibaba-inc.com, n-horiguchi@ah.jp.nec.com, ak@linux.intel.com, yongjun_wei@trendmicro.com.cn, mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20210104065843.5658-1-songmuchun@bytedance.com> From: Mike Kravetz Message-ID: Date: Mon, 4 Jan 2021 14:17:17 -0800 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: <20210104065843.5658-1-songmuchun@bytedance.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9854 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 phishscore=0 spamscore=0 malwarescore=0 mlxscore=0 mlxlogscore=999 suspectscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101040132 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9854 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 phishscore=0 priorityscore=1501 spamscore=0 mlxscore=0 clxscore=1011 bulkscore=0 lowpriorityscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101040133 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/3/21 10:58 PM, Muchun Song wrote: > If the refcount is one when it is migrated, it means that the page > was freed from under us. So we are done and do not need to migrate. > > Signed-off-by: Muchun Song > --- > mm/migrate.c | 6 ++++++ > 1 file changed, 6 insertions(+) Thanks! Reviewed-by: Mike Kravetz -- Mike Kravetz