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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 22B5CC43219 for ; Thu, 2 May 2019 18:34:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E66AF20675 for ; Thu, 2 May 2019 18:34:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YZubNvfw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726387AbfEBSeI (ORCPT ); Thu, 2 May 2019 14:34:08 -0400 Received: from mail-wr1-f41.google.com ([209.85.221.41]:38465 "EHLO mail-wr1-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726120AbfEBSeI (ORCPT ); Thu, 2 May 2019 14:34:08 -0400 Received: by mail-wr1-f41.google.com with SMTP id k16so4753091wrn.5 for ; Thu, 02 May 2019 11:34:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GtI5Tb9SFBI3B1ZJB/GXq7EgjI6y6AfHAArnGC6S7II=; b=YZubNvfw9f08VAVmYeysQ9beos02k15haIkRxMOFmawa+twb34tHDAQbpIGYDLf/ow 5scMUVXNBgM+9R19bmM9rwONYjqDAO+8yXQMhaFMXC9+x+G8n5t6QC0ow02qqGvxSqnO p4B/3upKa4Dy2JinaA++qF5jn6tWzlevr0IGMztZRAZ2YX8T5yHXGI9DRGPIufdbiufc D3XqtIdFVuAGXbzt1/il2mFUasHbp5p1XYlBj0IH4vGo6IYGnmEhUt+0kp2yhuss8Om/ mZDMUFUk8KSWKdj5ZYX04wKFB/VuaMAsq+wV6GkPq7jyN3xsnEgQKuvUYEuHjLyRZvHy rzUA== 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=GtI5Tb9SFBI3B1ZJB/GXq7EgjI6y6AfHAArnGC6S7II=; b=k90XIFfs7rZzgtRiuzxAnxDF77wI3tllvVToqVrRbd2y8NxVoQowCfSl7dB0Fyqiem HvSyBjwVEx4QDaSbvPBswXJT3et/vZ1fPi/20jVX+L0PEQPcCg5Z30HYKAld+5K2VnSO Fd8WHn+Q476FKkK4LLmtfHlQBEh8j3LiRQF6r7a7t30KpUdGIsbVf6ZwXmYwDQidXyWU lg8xCM+ZFrPy8rNUci25GBFdcXDwmUfM810HTKQcFujkNfguwxy0JJgTdgvTry+0DDyO mpQ2FgjKReSmKMbwfB5DvPoSX636x9Eo3YrWJlR6fhrbgj1aRlfjfcJATknPNlS6FyaC /zvA== X-Gm-Message-State: APjAAAU3yWE8cjPO7y9k+OgR0OBK29XqSNepwIYwhiYxKB4eV8yN5WPC rEnHdQoJenV3YgjEoiE2ETfeQXOmXxsRFrV0IOE= X-Google-Smtp-Source: APXvYqxnemZ2e4ppbL14WpVcnBspRgB/L+6moy8AKRGouftY1xWm19feySTLfd4DlRWcjMCCXtCpaNXUzjbeycD6yhY= X-Received: by 2002:a5d:5343:: with SMTP id t3mr4022565wrv.262.1556822046255; Thu, 02 May 2019 11:34:06 -0700 (PDT) MIME-Version: 1.0 References: <20190502040331.81196-1-ezemtsov@google.com> In-Reply-To: From: Richard Weinberger Date: Thu, 2 May 2019 20:33:55 +0200 Message-ID: Subject: Re: Initial patches for Incremental FS To: Amir Goldstein Cc: ezemtsov@google.com, linux-fsdevel , Theodore Tso , Miklos Szeredi Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, May 2, 2019 at 8:16 PM Richard Weinberger wrote: > > Piling logic into the kernel is not the answer. > > Adding the missing interfaces to the kernel is the answer. > > I wonder whether userfaultfd can but used for that use-case too? ...hit the send button too eary. My thought is, userfaultfd is used to support live migration of VMs such that pages from the remote side are loaded on demand. Sounds a little like the android app use-case, hm? The loader (ld-linux) runs the app and using userfaultfd missing pages get downloaded on demand. -- Thanks, //richard