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Tue, 15 Oct 2019 23:37:04 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9FNWwCl041669; Tue, 15 Oct 2019 23:37:03 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 2vn8ep8pam-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 15 Oct 2019 23:37:03 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x9FNb1jB002134; Tue, 15 Oct 2019 23:37:02 GMT Received: from [192.168.1.222] (/71.63.128.209) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 15 Oct 2019 23:37:01 +0000 Subject: Re: [PATCH] hugetlbfs: add O_TMPFILE support To: Michal Hocko , Piotr Sarna Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org References: <22c29acf9c51dae17802e1b05c9e5e4051448c5c.1571129593.git.p.sarna@tlen.pl> <20191015105055.GA24932@dhcp22.suse.cz> From: Mike Kravetz Message-ID: <766b4370-ba71-85a2-5a57-ca9ed7dc7870@oracle.com> Date: Tue, 15 Oct 2019 16:37:00 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <20191015105055.GA24932@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9411 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910150200 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9411 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910150200 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000006, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 10/15/19 3:50 AM, Michal Hocko wrote: > On Tue 15-10-19 11:01:12, Piotr Sarna wrote: >> With hugetlbfs, a common pattern for mapping anonymous huge pages >> is to create a temporary file first. > > Really? I though that this is normally done by shmget(SHM_HUGETLB) or > mmap(MAP_HUGETLB). Or maybe I misunderstood your definition on anonymous > huge pages. > >> Currently libraries like >> libhugetlbfs and seastar create these with a standard mkstemp+unlink >> trick, I would guess that much of libhugetlbfs was writen before MAP_HUGETLB was implemented. So, that is why it does not make (more) use of that option. The implementation looks to be straight forward. However, I really do not want to add more functionality to hugetlbfs unless there is specific use case that needs it. -- Mike Kravetz