From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753386AbYJFJuh (ORCPT ); Mon, 6 Oct 2008 05:50:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752441AbYJFJu3 (ORCPT ); Mon, 6 Oct 2008 05:50:29 -0400 Received: from one.firstfloor.org ([213.235.205.2]:60172 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752329AbYJFJu2 (ORCPT ); Mon, 6 Oct 2008 05:50:28 -0400 Date: Mon, 6 Oct 2008 11:56:28 +0200 From: Andi Kleen To: "Kirill A. Shutemov" Cc: Andi Kleen , Ingo Molnar , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andrew Morton Subject: Re: [PATCH] x86_64: Implement personality ADDR_LIMIT_32BIT Message-ID: <20081006095628.GE3180@one.firstfloor.org> References: <1223017469-5158-1-git-send-email-kirill@shutemov.name> <20081003080244.GC25408@elte.hu> <20081003092550.GA8669@localhost.localdomain> <87abdintds.fsf@basil.nowhere.org> <20081006081717.GA20072@localhost.localdomain> <20081006084246.GC3180@one.firstfloor.org> <20081006091709.GB20852@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081006091709.GB20852@localhost.localdomain> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > And personality() is not thread local/safe, so it's not a particularly > > good interface to use later. > > qemu can call personality() before any threads will be created. It still makes it unsuitable for a lot of other applications. e.g. a JVM using 32bit pointers couldn't use it because it would affect native C threads running in the same process. > > > Per system call switches are preferable > > and more flexible. > > Per syscall switches are cool, but I don't see any advantage from it for > qemu. Linux interfaces are not supposed to be "interfaces for qemu" but generally applicable interfaces. -Andi -- ak@linux.intel.com From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 6 Oct 2008 11:56:28 +0200 From: Andi Kleen Subject: Re: [PATCH] x86_64: Implement personality ADDR_LIMIT_32BIT Message-ID: <20081006095628.GE3180@one.firstfloor.org> References: <1223017469-5158-1-git-send-email-kirill@shutemov.name> <20081003080244.GC25408@elte.hu> <20081003092550.GA8669@localhost.localdomain> <87abdintds.fsf@basil.nowhere.org> <20081006081717.GA20072@localhost.localdomain> <20081006084246.GC3180@one.firstfloor.org> <20081006091709.GB20852@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081006091709.GB20852@localhost.localdomain> Sender: owner-linux-mm@kvack.org Return-Path: To: "Kirill A. Shutemov" Cc: Andi Kleen , Ingo Molnar , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andrew Morton List-ID: > > And personality() is not thread local/safe, so it's not a particularly > > good interface to use later. > > qemu can call personality() before any threads will be created. It still makes it unsuitable for a lot of other applications. e.g. a JVM using 32bit pointers couldn't use it because it would affect native C threads running in the same process. > > > Per system call switches are preferable > > and more flexible. > > Per syscall switches are cool, but I don't see any advantage from it for > qemu. Linux interfaces are not supposed to be "interfaces for qemu" but generally applicable interfaces. -Andi -- ak@linux.intel.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org