Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759088AbaGCSmP (ORCPT ); Thu, 3 Jul 2014 14:42:15 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:33332 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752570AbaGCSmO (ORCPT ); Thu, 3 Jul 2014 14:42:14 -0400 Message-ID: <53B5A343.4090402@linux.vnet.ibm.com> Date: Fri, 04 Jul 2014 00:08:59 +0530 From: Raghavendra K T Organization: IBM User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Linus Torvalds CC: Andrew Morton , Fengguang Wu , David Cohen , Al Viro , Damien Ramonda , Jan Kara , David Rientjes , Nishanth Aravamudan , linux-mm , Linux Kernel Mailing List Subject: Re: [PATCH] mm readahead: Fix sys_readahead breakage by reverting 2MB limit (bug 79111) References: <1404392547-11648-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <53B59CB5.9060004@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14070318-8878-0000-0000-00000D51937D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/03/2014 11:59 PM, Linus Torvalds wrote: > On Thu, Jul 3, 2014 at 11:22 AM, Linus Torvalds > wrote: >> >> So the bugzilla entry worries me a bit - we definitely do not want to >> regress in case somebody really relied on timing - but without more >> specific information I still think the real bug is just in the >> man-page. > > Side note: the 2MB limit may be too small. 2M is peanuts on modern > machines, even for fairly slow IO, and there are lots of files (like > glibc etc) that people might want to read-ahead during boot. We > already do bigger read-ahead if people just do "read()" system calls. > So I could certainly imagine that we should increase it. > > I do *not* think we should bow down to insane man-pages that have > always been wrong, though, and I don't think we should increase it to > "let's just read-ahead a whole ISO image" kind of sizes.. Okay, how about something like 256MB? I would be happy to send a patch for that change. -- 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/