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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 A0BD1C169C4 for ; Mon, 11 Feb 2019 21:15:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 62CE8214DA for ; Mon, 11 Feb 2019 21:15:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 62CE8214DA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0E47D8E0167; Mon, 11 Feb 2019 16:15:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0928F8E0165; Mon, 11 Feb 2019 16:15:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E76408E0167; Mon, 11 Feb 2019 16:15:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by kanga.kvack.org (Postfix) with ESMTP id 9FF278E0165 for ; Mon, 11 Feb 2019 16:15:00 -0500 (EST) Received: by mail-pf1-f199.google.com with SMTP id k10so328699pfi.5 for ; Mon, 11 Feb 2019 13:15:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:thread-topic:thread-index:date:message-id:references :in-reply-to:accept-language:content-language:dlp-product :dlp-version:dlp-reaction:content-transfer-encoding:mime-version; bh=8YyqeJuE3a+YmuZJDfL3AeKrem/uQr8+IZ/9CeD+Mbc=; b=it/8NRDQdUq4FFm/x2ZM4IeKv6Z9IhMJ6+GxMOcxCnvunySzWD18Ztf3GjCAJW6aCr fEnyr4CAcWkEeWgvv8l8fDFFpsi83Wc2QDzez5NIopgTD/p13pl9rgDOmcf+pydM4D5w XwjoYGxeEsGaKPn+78WYJ5DtnYFL1WrDWRuVbGcF6YW+Z74WfHKF25pcVnP5TO+G0+SV 3SZay6pce4kkUCLfmmdl8+NTwD8/OAjR1T6pdOd24lqergWYz9QT+jYRgJyikXDemQ3y zJWzVDXDRIJ8kt6WkSdjTuAlDK2djDrspI5m3by8kBxgzNstxZAOaQqjSdRIfu+FN3nl F2kw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of ira.weiny@intel.com designates 192.55.52.43 as permitted sender) smtp.mailfrom=ira.weiny@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: AHQUAuYedf9ZbMkslHolwetk+4bho8EFUG430oPLOWHHpF1pNyTkyKBe Bvd3siOc3Dzyksecp8jsuOoBilomdQy/pjHTbyTXXHC49Wnd22lLgzQtLFDGL31wRxoI0fJlqvz zswgZAv4O6HFZ3v3neORQuUXWuKjll32LDHBKuZkYtE7xGbLQhmjE5a/Y59r6Y9WRyQ== X-Received: by 2002:a62:f54d:: with SMTP id n74mr285857pfh.98.1549919700345; Mon, 11 Feb 2019 13:15:00 -0800 (PST) X-Google-Smtp-Source: AHgI3IY0jQOVuPk9TaXwZ+a20Oq27Piny2DiugFE7biUbkKOM8heY4p1MhUyG3C2wExZMeVDYd0G X-Received: by 2002:a62:f54d:: with SMTP id n74mr285812pfh.98.1549919699710; Mon, 11 Feb 2019 13:14:59 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1549919699; cv=none; d=google.com; s=arc-20160816; b=yxKLV1Y/5JtLtJne9vs4BwAX0pD8dBICglcwj/UEA8mUTMUaGXPgEP9o++UFBOYYRi tyIxNiJ/QQqupVSmprNEM2kCfcxNK+B2+mD09MgjJaDCZRGCWnmtTkygDRknovarEFzW /bx99zDI47M/Vcdso9q2/4+M64zXporcSuqLMjqU8a39FlNT99cT0uoggFYbV6OAdmti LFoFi0Yd/R6QjAE45B8msGAnN7C4pjQNSMROB5OJsIjRt0R941KgjQmzqXdV3KAXlqMO RTJpopOIOekMDCggqgLSnTxi8p/H7SpaeSzgbLwc3TKf97u7HkCgADS0cSqZjX3H3NRG YUAA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:content-transfer-encoding:dlp-reaction:dlp-version :dlp-product:content-language:accept-language:in-reply-to:references :message-id:date:thread-index:thread-topic:subject:cc:to:from; bh=8YyqeJuE3a+YmuZJDfL3AeKrem/uQr8+IZ/9CeD+Mbc=; b=haNerhE99AvF6nxoMMzZvSLb1qQz5+H3zkS2tEudQo6JlgZiQ+j2XP0mXaAoEG05M7 JpiU4yO2LbXEuw6Z2VJTbtM5TMqKeNoztdnncWyRHlZkczdWMw5nIq3vJbkAgxFjFicY LWJc7pRdkI6W7Vq8Woez1KFVr7NlZML6WkbOxJ+uMOZNz1hnriTd+8nw/A5fMsZw7+GG ldobqWZ4WIaQGbyJ33IoxYssR6z5t7+/nt3quKPD68upSMT35an9SXtBi4A4CqiohB9A JArMZQ6CiipHZLoNyGbS5znvD3soq7paCbd/dUIM1bIlqLhPpo04icswGOVRBB5Bt/HC G6IA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of ira.weiny@intel.com designates 192.55.52.43 as permitted sender) smtp.mailfrom=ira.weiny@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga05.intel.com (mga05.intel.com. [192.55.52.43]) by mx.google.com with ESMTPS id z128si10231706pgb.372.2019.02.11.13.14.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 13:14:59 -0800 (PST) Received-SPF: pass (google.com: domain of ira.weiny@intel.com designates 192.55.52.43 as permitted sender) client-ip=192.55.52.43; Authentication-Results: mx.google.com; spf=pass (google.com: domain of ira.weiny@intel.com designates 192.55.52.43 as permitted sender) smtp.mailfrom=ira.weiny@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Feb 2019 13:14:59 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,360,1544515200"; d="scan'208";a="145995188" Received: from fmsmsx107.amr.corp.intel.com ([10.18.124.205]) by fmsmga001.fm.intel.com with ESMTP; 11 Feb 2019 13:14:59 -0800 Received: from fmsmsx112.amr.corp.intel.com (10.18.116.6) by fmsmsx107.amr.corp.intel.com (10.18.124.205) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 11 Feb 2019 13:14:58 -0800 Received: from crsmsx103.amr.corp.intel.com (172.18.63.31) by FMSMSX112.amr.corp.intel.com (10.18.116.6) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 11 Feb 2019 13:14:58 -0800 Received: from crsmsx101.amr.corp.intel.com ([169.254.1.57]) by CRSMSX103.amr.corp.intel.com ([169.254.4.180]) with mapi id 14.03.0415.000; Mon, 11 Feb 2019 15:14:56 -0600 From: "Weiny, Ira" To: Jason Gunthorpe CC: "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Daniel Borkmann , Davidlohr Bueso , "netdev@vger.kernel.org" , "Marciniszyn, Mike" , "Dalessandro, Dennis" , Doug Ledford , "Andrew Morton" , "Kirill A. Shutemov" , "Williams, Dan J" Subject: RE: [PATCH 0/3] Add gup fast + longterm and use it in HFI1 Thread-Topic: [PATCH 0/3] Add gup fast + longterm and use it in HFI1 Thread-Index: AQHUwkbGJiw3VF3kpESe1yhfT7MilqXbdCyA//+kDNA= Date: Mon, 11 Feb 2019 21:14:56 +0000 Message-ID: <2807E5FD2F6FDA4886F6618EAC48510E79BCF04C@CRSMSX101.amr.corp.intel.com> References: <20190211201643.7599-1-ira.weiny@intel.com> <20190211204049.GB2771@ziepe.ca> In-Reply-To: <20190211204049.GB2771@ziepe.ca> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiMDFlNTkxMjgtNDFmNi00OWJhLWIxNDUtZmUwNDU4NzYzYjBhIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiQytYTmd4U0ErY3oyVTdaUEw3K3VoZjBEOHlcL0hmcWI0ZmlWXC9uRVhLNHRNZGlhbGNtSVJFaEhRa3JjN1wvSERYRCJ9 x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.400.15 dlp-reaction: no-action x-originating-ip: [172.18.205.10] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 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: >=20 > On Mon, Feb 11, 2019 at 12:16:40PM -0800, ira.weiny@intel.com wrote: > > From: Ira Weiny > > > > NOTE: This series depends on my clean up patch to remove the write > > parameter from gup_fast_permitted()[1] > > > > HFI1 uses get_user_pages_fast() due to it performance advantages. > > Like RDMA, > > HFI1 pages can be held for a significant time. But > > get_user_pages_fast() does not protect against mapping of FS DAX pages. >=20 > If HFI1 can use the _fast varient, can't all the general RDMA stuff use i= t too? >=20 > What is the guidance on when fast vs not fast should be use? Right now it can't because it holds mmap_sem across the call. Once Shiraz'= s patches are accepted removing the umem->hugetlb flag I think we can chang= e umem.c. Also, it specifies FOLL_FORCE which can't currently be specified with gup f= ast. One idea I had was to change get_user_pages_fast() to use gup_flags i= nstead of a single write flag. But that proved to be a very big cosmetic c= hange across a lot of callers so I went this way. Ira >=20 > Jason