From: Andy Lutomirski Subject: Re: page fault scalability (ext3, ext4, xfs) Date: Wed, 14 Aug 2013 16:38:12 -0700 Message-ID: References: <520BB9EF.5020308@linux.intel.com> <20130814194359.GA22316@thunk.org> <520BED7A.4000903@intel.com> <20130814230648.GD22316@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: "Theodore Ts'o" , Dave Hansen , Dave Hansen , linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, Jan Kara , LKML , david@fromorbit.com, Tim Chen , Andi Kleen , Andy Lutomirski Return-path: In-Reply-To: <20130814230648.GD22316@thunk.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Wed, Aug 14, 2013 at 4:06 PM, Theodore Ts'o wrote: > On Wed, Aug 14, 2013 at 01:50:02PM -0700, Dave Hansen wrote: >> >> Would a plain old fallocate() do the trick, or does it actually need >> zeros written to it? > > It would be better to write zeros to it, so we aren't measuring the > cost of the unwritten->written conversion. At the risk of beating a dead horse, how hard would it be to defer this part until writeback? --Andy