Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751315AbXB1U3E (ORCPT ); Wed, 28 Feb 2007 15:29:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751900AbXB1U3E (ORCPT ); Wed, 28 Feb 2007 15:29:04 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:52297 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751315AbXB1U3A (ORCPT ); Wed, 28 Feb 2007 15:29:00 -0500 Date: Wed, 28 Feb 2007 21:21:56 +0100 From: Ingo Molnar To: Davide Libenzi Cc: Ulrich Drepper , Linux Kernel Mailing List , Linus Torvalds , Arjan van de Ven , Christoph Hellwig , Andrew Morton , Alan Cox , Zach Brown , Evgeniy Polyakov , "David S. Miller" , Suparna Bhattacharya , Jens Axboe , Thomas Gleixner Subject: Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3 Message-ID: <20070228202156.GA15846@elte.hu> References: <20070221211355.GA7302@elte.hu> <20070221233111.GB5895@elte.hu> <45DCD9E5.2010106@redhat.com> <20070222074044.GA4158@elte.hu> <20070228094522.GA17716@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1420 Lines: 38 * Davide Libenzi wrote: > My point is, the syslet infrastructure is expensive for the kernel in > terms of compat, [...] it is not. Today i've implemented 64-bit syslets on x86_64 and 32-bit-on-64-bit compat syslets. Both the 64-bit and the 32-bit syslet (and threadlet) binaries work just fine on a 64-bit kernel, and they share 99% of the infrastructure. There's only a single #ifdef CONFIG_COMPAT in kernel/async.c: #ifdef CONFIG_COMPAT asmlinkage struct syslet_uatom __user * compat_sys_async_exec(struct syslet_uatom __user *uatom, struct async_head_user __user *ahu) { return __sys_async_exec(uatom, ahu, &compat_sys_call_table, compat_NR_syscalls); } #endif Even mixed-mode syslets should work (although i havent specifically tested them), where the head switches between 64-bit and 32-bit mode and submits syslets from both 64-bit and from 32-bit mode, and at the same time there might be both 64-bit and 32-bit syslets 'in flight'. But i'm happy to change the syslet API in any sane way, and did so based on feedback from Jens who is actually using them. Ingo - 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/