Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758849AbaGCPmB (ORCPT ); Thu, 3 Jul 2014 11:42:01 -0400 Received: from mail-ve0-f177.google.com ([209.85.128.177]:40238 "EHLO mail-ve0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757786AbaGCPl7 (ORCPT ); Thu, 3 Jul 2014 11:41:59 -0400 MIME-Version: 1.0 In-Reply-To: <1404392547-11648-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> References: <1404392547-11648-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> Date: Thu, 3 Jul 2014 08:41:58 -0700 X-Google-Sender-Auth: 2dUmddIb-ZHdf3CoaYFWMfBfEz4 Message-ID: Subject: Re: [PATCH] mm readahead: Fix sys_readahead breakage by reverting 2MB limit (bug 79111) From: Linus Torvalds To: Raghavendra K T Cc: Andrew Morton , Fengguang Wu , David Cohen , Al Viro , Damien Ramonda , Jan Kara , David Rientjes , Nishanth Aravamudan , linux-mm , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 3, 2014 at 6:02 AM, Raghavendra K T wrote: > > However it broke sys_readahead semantics: 'readahead() blocks until the specified > data has been read' What? Where did you find that insane sentence? And where did you find an application that depends on that totally insane semantics that sure as hell was never intentional. If this comes from some man-page, then the man-page is just full of sh*t, and is being crazy. The whole and *only* point of readahead() is that it does *not* block, and you can do it across multiple files. So NAK NAK NAK. This is insane and completely wrong. And the bugzilla is crazy too. Why would anybody think that readahead() is the same as read()? Linus -- 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/