From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 21 May 2002 16:27:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 21 May 2002 16:27:55 -0400 Received: from e31.co.us.ibm.com ([32.97.110.129]:47787 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id ; Tue, 21 May 2002 16:27:54 -0400 Date: Tue, 21 May 2002 15:27:48 -0500 From: Dave McCracken To: Linux Kernel cc: Linus Torvalds Subject: [RFC] POSIX personality Message-ID: <64270000.1022012868@baldur.austin.ibm.com> X-Mailer: Mulberry/2.2.0 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org As part of improving support for POSIX multithreading I've been putting together some patches to allow more things to be shared between tasks. Right now this is accomplished via flags to clone() with one flag per resource to be shared. This usually translates to a data structure pointed to out of task_struct, complete with reference count and lock. In a discussion today an alternate idea was proposed by Ben LaHaise. He suggested creating a POSIX personality, or execution domain. This would take some pressure off the clone flag space as well as allowing some optimizations in the code. It could also be used in situations where POSIX-compatible behavior entails more than just sharing extra resources between tasks. This would assume that the resources I'm sharing would only be useful for POSIX compatibility, but at this point it seems unlikely that anyone would want to share a subset of them. The resources I'm currently working on include credentials, signals, and timers, and there's a patch available for semaphore undo that could also be part of this mechanism. Since you've made it this far my question to you all is this: assuming that we do want improved POSIX compatibility does this sound like a reasonable way to add it? Thanks, Dave McCracken ====================================================================== Dave McCracken IBM Linux Base Kernel Team 1-512-838-3059 dmccr@us.ibm.com T/L 678-3059