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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 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 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