Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752345Ab0AMSlq (ORCPT ); Wed, 13 Jan 2010 13:41:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751118Ab0AMSlo (ORCPT ); Wed, 13 Jan 2010 13:41:44 -0500 Received: from qmta01.emeryville.ca.mail.comcast.net ([76.96.30.16]:33087 "EHLO qmta01.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751402Ab0AMSln (ORCPT ); Wed, 13 Jan 2010 13:41:43 -0500 Subject: Re: [RFC PATCH] introduce sys_membarrier(): process-wide memory barrier (v5) From: Nicholas Miell To: Mathieu Desnoyers Cc: paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, Steven Rostedt , Oleg Nesterov , Peter Zijlstra , Ingo Molnar , akpm@linux-foundation.org, josh@joshtriplett.org, tglx@linutronix.de, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, laijs@cn.fujitsu.com, dipankar@in.ibm.com In-Reply-To: <20100113182442.GA20704@Krystal> References: <20100113013757.GA29314@Krystal> <1263358823.3874.10.camel@entropy> <20100113053126.GC6781@linux.vnet.ibm.com> <1263361196.3874.12.camel@entropy> <20100113143805.GC30875@Krystal> <1263406071.3874.16.camel@entropy> <20100113182442.GA20704@Krystal> Content-Type: text/plain; charset="UTF-8" Date: Wed, 13 Jan 2010 10:41:38 -0800 Message-ID: <1263408098.3874.19.camel@entropy> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 (2.28.2-1.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 945 Lines: 28 On Wed, 2010-01-13 at 13:24 -0500, Mathieu Desnoyers wrote: > * Nicholas Miell (nmiell@comcast.net) wrote: > > > The whole point of compat and incompat flags is that it allows new > > applications to run on old kernels and either work or fail as > > appropriate, depending on whether the new features they're using must be > > implemented or can be silently ignored. > > I see. Thanks for the explanation. Then the expedited flag should > clearly be part of the mandatory flags. > > Can you point me to other system calls that are doing this ? > > Thanks, > > Mathieu Not off the top of my head, but I did steal the idea from the ext2/3/4 disk format. -- Nicholas Miell -- 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/