From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755626Ab1K2R5r (ORCPT ); Tue, 29 Nov 2011 12:57:47 -0500 Received: from one.firstfloor.org ([213.235.205.2]:48718 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753580Ab1K2R5q (ORCPT ); Tue, 29 Nov 2011 12:57:46 -0500 Date: Tue, 29 Nov 2011 18:57:43 +0100 From: Andi Kleen To: Wu Fengguang Cc: Andrew Morton , Andi Kleen , Ingo Molnar , Jens Axboe , Peter Zijlstra , Rik van Riel , Linux Memory Management List , linux-fsdevel@vger.kernel.org, LKML Subject: Re: [PATCH 3/9] readahead: record readahead patterns Message-ID: <20111129175743.GP24062@one.firstfloor.org> References: <20111129130900.628549879@intel.com> <20111129131456.278516066@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111129131456.278516066@intel.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 29, 2011 at 09:09:03PM +0800, Wu Fengguang wrote: > Record the readahead pattern in ra->pattern and extend the ra_submit() > parameters, to be used by the next readahead tracing/stats patches. I like this, could it be exported it a bit more formally in /proc for each file descriptor? I could imagine a monitoring tool that you run on a process that tells you what pattern state the various file descriptors are in and how large the window is. That would be similar to the tools for monitoring network connections, which are extremly useful in practice. -Andi