From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751537AbaCVRDg (ORCPT ); Sat, 22 Mar 2014 13:03:36 -0400 Received: from imap.thunk.org ([74.207.234.97]:44753 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751240AbaCVRDb (ORCPT ); Sat, 22 Mar 2014 13:03:31 -0400 Date: Sat, 22 Mar 2014 13:03:22 -0400 From: tytso@mit.edu To: Andrew Morton Cc: Fabian Frederick , linux-kernel , reiserfs-devel@vger.kernel.org Subject: Re: [RFC 1/1] fs/reiserfs/journal.c: Remove obsolete __GFP_NOFAIL Message-ID: <20140322170322.GA23583@thunk.org> Mail-Followup-To: tytso@mit.edu, Andrew Morton , Fabian Frederick , linux-kernel , reiserfs-devel@vger.kernel.org References: <20140321171830.ef47fdea1a3a2f2921c8fe86@skynet.be> <20140321130055.c0ea32946f3543cd7f6bedd6@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140321130055.c0ea32946f3543cd7f6bedd6@linux-foundation.org> User-Agent: Mutt/1.5.22 (2013-10-16) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 21, 2014 at 01:00:55PM -0700, Andrew Morton wrote: > > The whole point of __GFP_NOFAIL is to centralise this > wait-for-memory-for-ever operation. So it is implemented in a common > (core) place and so that we can easily locate these problematic > callers. > > is exactly wrong. Yes, we'd like __GFP_NOFAIL to go away, but it > cannot go away until buggy callsites such as this one are *fixed*. > Removing the __GFP_NOFAIL usage simply hides the buggy code from casual > searchers. The change to jbd2 was made in July 2010, back when the "we must exterminate GFP_NOFAIL at all costs" brigade was in high gear, and the folks claiming that GFP_FAIL *would* go away, come hell or high water, was a bit more emphatic. I'll note that since 2011, there has been precious little movement on removing the final few callers of GFP_NOFAIL, and we still have a bit under two dozen of them, including a new one in fs/buffer.c that was added in 2013. In any case, __GFP_NOFAIL is in the code comments, so a casual searcher would find it pretty quickly with a "git grep". - Ted