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Mon, 21 Oct 2019 17:17:20 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9LH9TcB081920; Mon, 21 Oct 2019 17:17:19 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 2vrcmnjbws-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 21 Oct 2019 17:17:19 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x9LHHF4m004720; Mon, 21 Oct 2019 17:17:18 GMT Received: from [192.168.1.222] (/71.63.128.209) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 21 Oct 2019 10:17:14 -0700 Subject: Re: [PATCH] hugetlbfs: add O_TMPFILE support From: Mike Kravetz To: Piotr Sarna Cc: Michal Hocko , 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> <766b4370-ba71-85a2-5a57-ca9ed7dc7870@oracle.com> Message-ID: Date: Mon, 21 Oct 2019 10:17:13 -0700 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: <766b4370-ba71-85a2-5a57-ca9ed7dc7870@oracle.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=9417 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=954 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910210163 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9417 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=1015 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-1910210164 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 10/15/19 4:37 PM, Mike Kravetz wrote: > 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. It was not my intention to shut down discussion on this patch. I was just asking if there was a (new) use case for such a change. I am checking with our DB team as I seem to remember them using the create/unlink approach for hugetlbfs in one of their upcoming models. Is there a new use case you were thinking about? -- Mike Kravetz