From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756171Ab2EAVGj (ORCPT ); Tue, 1 May 2012 17:06:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37541 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751868Ab2EAVGh (ORCPT ); Tue, 1 May 2012 17:06:37 -0400 Message-ID: <4FA0504D.60802@redhat.com> Date: Tue, 01 May 2012 17:06:21 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120329 Thunderbird/11.0.1 MIME-Version: 1.0 To: Johannes Weiner CC: linux-mm@kvack.org, Andrea Arcangeli , Peter Zijlstra , Mel Gorman , Andrew Morton , Minchan Kim , Hugh Dickins , KOSAKI Motohiro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 1/5] mm: readahead: move radix tree hole searching here References: <1335861713-4573-1-git-send-email-hannes@cmpxchg.org> <1335861713-4573-2-git-send-email-hannes@cmpxchg.org> In-Reply-To: <1335861713-4573-2-git-send-email-hannes@cmpxchg.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/01/2012 04:41 AM, Johannes Weiner wrote: > The readahead code searches the page cache for non-present pages, or > holes, to get a picture of the area surrounding a fault e.g. > > For this it sufficed to rely on the radix tree definition of holes, > which is "empty tree slot". This is about to change, though, because > shadow page descriptors will be stored in the page cache when the real > pages get evicted from memory. > > Fortunately, nobody outside the readahead code uses these functions > and they have no internal knowledge of the radix tree structures, so > just move them over to mm/readahead.c where they can later be adapted > to handle the new definition of "page cache hole". > > Signed-off-by: Johannes Weiner Reviewed-by: Rik van Riel -- All rights reversed