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[209.132.180.67]) by mx.google.com with ESMTP id 3si16109191plx.386.2019.03.25.15.38.32; Mon, 25 Mar 2019 15:38:48 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@intel-com.20150623.gappssmtp.com header.s=20150623 header.b=GiML85P6; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730542AbfCYWgl (ORCPT + 99 others); Mon, 25 Mar 2019 18:36:41 -0400 Received: from mail-ot1-f66.google.com ([209.85.210.66]:45890 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729681AbfCYWgl (ORCPT ); Mon, 25 Mar 2019 18:36:41 -0400 Received: by mail-ot1-f66.google.com with SMTP id e5so9625573otk.12 for ; Mon, 25 Mar 2019 15:36:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=sTcPY30C0OSYzeNRaa/EPMGmie/8U7JXyLn50zJf1Pw=; b=GiML85P6LCslgtDlslKCCUhWvbv1y+nvEc56Q0X8Qjel5DMzDzfar6+H7s6fmu2h3d dLEyyqXH0XMmCTgsIn3yhKqlcM+JBYc0UTK5/fEknfFXNcWh7vZB4qk8YZDtnv5IAp1l JJmvxmcMseSRffwnab8HmvfayPrxqWL01+eSLrgeJSA/9velnAvwDxgjJF0ugNsd/ZFW LpEP4qbgPu6yg3gM3ufLilvbIHnGxS7z2m60QKWTsLURCVB/tyWdotVRQdzsF7WEone8 YAzkam1P/6bRoe78GssUpwMMiqKYpvFyZCQg0hkxWxLA+GhGDSF3+u1c5KgRvgkutwHN +uoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=sTcPY30C0OSYzeNRaa/EPMGmie/8U7JXyLn50zJf1Pw=; b=ohyK6GulsnSQ6veAbmpuXsFosErWq+e4E6kwg4y0D4gzCjUGbZOOWNmSsWA8iBmTkp ZBzkKQvlCDm4sSKTikUGirZ1xUyb4hduJ3OeD+vZofnozgWxDMY+kOTILyW+Pd/qjkR2 w3Ve24fWvbIb9vsIZS8M5CndBjYduXDxvSYpURV4eIzumI3zv6LjLUyel1X/TK3N/HEC kMAkmWZOExE0yXNQWfWRx4hrAt5HCDnkGlOxlvdpFiiDKW5gN1pmvbpb+dTcHiBaJ1lX 43EvvXX5dkYpj/z5R/fLTduDkgmQYDaQml565AXKH4TGfmq3Ue38oAQSKzOaa7Ai8d5a M/2A== X-Gm-Message-State: APjAAAWx9c7hw3Wxi77HHroJ9IhKeRuNL4MO+aGZ7iBexBfdVjIIdqIy jaYRsI1NF7/XTKDtBWG2k7YBJApXNhxJfxJ3n8B31Q== X-Received: by 2002:a9d:224a:: with SMTP id o68mr20655282ota.214.1553553400410; Mon, 25 Mar 2019 15:36:40 -0700 (PDT) MIME-Version: 1.0 References: <20190317183438.2057-1-ira.weiny@intel.com> <20190317183438.2057-5-ira.weiny@intel.com> <20190325084225.GC16366@iweiny-DESK2.sc.intel.com> <20190325164713.GC9949@ziepe.ca> <20190325092314.GF16366@iweiny-DESK2.sc.intel.com> <20190325175150.GA21008@ziepe.ca> <20190325142125.GH16366@iweiny-DESK2.sc.intel.com> In-Reply-To: <20190325142125.GH16366@iweiny-DESK2.sc.intel.com> From: Dan Williams Date: Mon, 25 Mar 2019 15:36:28 -0700 Message-ID: Subject: Re: [RESEND 4/7] mm/gup: Add FOLL_LONGTERM capability to GUP fast To: Ira Weiny Cc: Jason Gunthorpe , Andrew Morton , John Hubbard , Michal Hocko , "Kirill A. Shutemov" , Peter Zijlstra , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , Martin Schwidefsky , Heiko Carstens , Rich Felker , Yoshinori Sato , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Ralf Baechle , James Hogan , linux-mm , Linux Kernel Mailing List , linux-mips@vger.kernel.org, linuxppc-dev , linux-s390 , Linux-sh , sparclinux@vger.kernel.org, linux-rdma , "netdev@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 25, 2019 at 3:22 PM Ira Weiny wrote: [..] > FWIW this thread is making me think my original patch which simply implemented > get_user_pages_fast_longterm() would be more clear. There is some evidence > that the GUP API was trending that way (see get_user_pages_remote). That seems > wrong but I don't know how to ensure users don't specify the wrong flag. What about just making the existing get_user_pages_longterm() have a fast path option?