Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753971AbbEKQYQ (ORCPT ); Mon, 11 May 2015 12:24:16 -0400 Received: from cobra.newdream.net ([66.33.216.30]:55652 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753910AbbEKQYK (ORCPT ); Mon, 11 May 2015 12:24:10 -0400 Date: Mon, 11 May 2015 09:24:09 -0700 (PDT) From: Sage Weil To: "Theodore Ts'o" cc: Trond Myklebust , Dave Chinner , Zach Brown , Alexander Viro , Linux FS-devel Mailing List , Linux Kernel Mailing List , Linux API Mailing List Subject: Re: [PATCH RFC] vfs: add a O_NOMTIME flag In-Reply-To: <20150511144719.GA14088@thunk.org> Message-ID: References: <1430949612-21356-1-git-send-email-zab@redhat.com> <20150507002617.GJ4327@dastard> <20150507172053.GA659@lenny.home.zabbo.net> <20150508221325.GM4327@dastard> <20150511144719.GA14088@thunk.org> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1116 Lines: 25 On Mon, 11 May 2015, Theodore Ts'o wrote: > On Sun, May 10, 2015 at 07:13:24PM -0400, Trond Myklebust wrote: > > That makes it completely non-generic though. By putting this in the > > VFS, you are giving applications a loaded gun that is pointed straight > > at the application user's head. > > Let me re-ask the question that I asked last week (and was apparently > ignored). Why not trying to use the lazytime feature instead of > pointing a head straight at the application's --- and system > administrators' --- heads? Sorry Ted, I thought I responded already. The goal is to avoid inode writeout entirely when we can, and as I understand it lazytime will still force writeout before the inode is dropped from the cache. In systems like Ceph in particular, the IOs can be spread across lots of files, so simply deferring writeout doesn't always help. sage -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/