Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757705AbZFWV0W (ORCPT ); Tue, 23 Jun 2009 17:26:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754527AbZFWV0M (ORCPT ); Tue, 23 Jun 2009 17:26:12 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:57359 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754517AbZFWV0L (ORCPT ); Tue, 23 Jun 2009 17:26:11 -0400 Date: Tue, 23 Jun 2009 14:25:11 -0700 From: Andrew Morton To: Davide Libenzi Cc: linux-kernel@vger.kernel.org, avi@redhat.com, kvm@vger.kernel.org, ghaskins@novell.com, rusty@rustcorp.com.au, bcrl@kvack.org Subject: Re: [patch] eventfd - revised interface and cleanups (2nd rev) Message-Id: <20090623142511.c9068655.akpm@linux-foundation.org> In-Reply-To: References: <20090623131239.711d9f83.akpm@linux-foundation.org> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1616 Lines: 36 On Tue, 23 Jun 2009 13:59:07 -0700 (PDT) Davide Libenzi wrote: > On Tue, 23 Jun 2009, Andrew Morton wrote: > > > On Tue, 23 Jun 2009 12:25:36 -0700 (PDT) > > Davide Libenzi wrote: > > > > > Another cleanup this patch does, is making AIO select EVENTFD, instead of > > > adding a bunch of empty function stubs inside eventfd.h in order to > > > handle the (AIO && !EVENTFD) case. > > > > Given that we're trying to squeak this patch into 2.6.31, it's quite > > unfortunate to include unrelated changes. Especially ones which > > involve the always-problematic "select". Although this one looks less > > than usually deadly due to the simple dependencies of AIO and eventfd. > > > > However... > > > > Is this a good way of fixing the (AIO && !EVENTFD) case? Surely if the > > developer selected this combination, he doesn't want to carry the > > overhead of including eventfd. IOW, if AIO can work acceptably without > > eventfd being compiled into the kernel then adding the stubs is a > > superior solution. > > IMO when someone says "AIO included in the kernel", should get the whole > AIO functionality and not part of it. > People already started using KAIO+eventfd, and a (AIO && !EVENTFD) config > will make their code fail. That isn't for us to decide. Entire syscalls can be disabled in config. -- 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/