From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932613AbWFCL0S (ORCPT ); Sat, 3 Jun 2006 07:26:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932614AbWFCL0S (ORCPT ); Sat, 3 Jun 2006 07:26:18 -0400 Received: from tomts16.bellnexxia.net ([209.226.175.4]:35024 "EHLO tomts16-srv.bellnexxia.net") by vger.kernel.org with ESMTP id S932613AbWFCL0R (ORCPT ); Sat, 3 Jun 2006 07:26:17 -0400 Date: Sat, 3 Jun 2006 07:26:17 -0400 From: Mathieu Desnoyers To: linux-kernel@vger.kernel.org, ltt-dev@shafik.org Subject: Per CPU non locked atomic operations Message-ID: <20060603112617.GB14581@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.31-grsec (i686) X-Uptime: 07:20:02 up 28 days, 14:29, 3 users, load average: 1.11, 1.87, 1.99 User-Agent: Mutt/1.5.11+cvs20060403 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, In the kernel tracer I develop (LTTng : http://ltt.polymtl.ca), I see a need that could be shared by others : I extensively use per-CPU data structures to provide efficient tracing. In addition to that, I use atomic operations (cmpxchg and atomic increment) to keep track of offsets in the buffer so it can be reentrant with NMI handlers. Would there be some larger interest for having non LOCK prefixed versions of atomic.h functions and cmpxchg for per-CPU variable purposes ? Mathieu OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68