From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754294Ab0AaVMS (ORCPT ); Sun, 31 Jan 2010 16:12:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753299Ab0AaVMR (ORCPT ); Sun, 31 Jan 2010 16:12:17 -0500 Received: from smtp.polymtl.ca ([132.207.4.11]:60138 "EHLO smtp.polymtl.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753022Ab0AaVMQ (ORCPT ); Sun, 31 Jan 2010 16:12:16 -0500 X-Greylist: delayed 565 seconds by postgrey-1.27 at vger.kernel.org; Sun, 31 Jan 2010 16:12:16 EST Message-Id: <20100131205254.407214951@polymtl.ca> User-Agent: quilt/0.46-1 Date: Sun, 31 Jan 2010 15:52:54 -0500 From: Mathieu Desnoyers To: Linus Torvalds , akpm@linux-foundation.org, Ingo Molnar , linux-kernel@vger.kernel.org, KOSAKI Motohiro , Steven Rostedt , "Paul E. McKenney" , Nicholas Miell , laijs@cn.fujitsu.com, dipankar@in.ibm.com, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com Subject: [patch 0/3] introduce sys_membarrier(): process-wide memory barrier (v8) X-Poly-FromMTA: (test.casi.polymtl.ca [132.207.72.60]) at Sun, 31 Jan 2010 21:00:13 +0000 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Here is an updated version of the sys_membarrier system call. It implements a system call that allows userspace to distribute the overhead of memory barriers asymmetrically. It is particularly useful for Userspace RCU (liburcu), to allow the RCU read-side to only issue compiler barriers, matched by calls to sys_membarrier() in the userspace synchronize_rcu(). Even though sys_membarrier should be portable to other architecture as-is without arch-specific modifications, I propose to incrementally reserve the system call IDs as we test it on each architecture. Here is a version that I think should be ready for merging. It is based on the 2.6.33-rc6 kernel. I would appreciate if people who gave their Acked-by in the RFC rounds could confirm their Acked-by following the patch set updates. Thanks, Mathieu -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68