From: Jeff Garzik Subject: Re: [PATCH, RFC 0/3] Introduce new O_HOT and O_COLD flags Date: Sat, 21 Apr 2012 14:26:43 -0400 Message-ID: <4F92FBE3.50709@garzik.org> References: <1334863211-19504-1-git-send-email-tytso@mit.edu> <4F912880.70708@panasas.com> <1334919662.5879.23.camel@dabdike> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Lukas Czerner , Boaz Harrosh , Theodore Ts'o , linux-fsdevel@vger.kernel.org, Ext4 Developers List , linux-mm@kvack.org To: James Bottomley Return-path: Received: from mail-vb0-f46.google.com ([209.85.212.46]:59885 "EHLO mail-vb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751240Ab2DUS0q (ORCPT ); Sat, 21 Apr 2012 14:26:46 -0400 In-Reply-To: <1334919662.5879.23.camel@dabdike> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 04/20/2012 07:01 AM, James Bottomley wrote: > The concern I have is that the notion of hot and cold files *isn't* > propagated to the page cache, it's just shared between the fs and the > disk. Bingo -- full-file hint is too coarse-grained for some workloads. Page granularity would propagate to the VM as well as block layer, and give the required flexibility to all workloads. As well as covering the full-file case. Jeff