Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751972AbXB1VJu (ORCPT ); Wed, 28 Feb 2007 16:09:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751973AbXB1VJu (ORCPT ); Wed, 28 Feb 2007 16:09:50 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:4873 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751972AbXB1VJt (ORCPT ); Wed, 28 Feb 2007 16:09:49 -0500 X-AuthUser: davidel@xmailserver.org Date: Wed, 28 Feb 2007 13:09:47 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Ingo Molnar 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 In-Reply-To: <20070228202156.GA15846@elte.hu> Message-ID: References: <20070221211355.GA7302@elte.hu> <20070221233111.GB5895@elte.hu> <45DCD9E5.2010106@redhat.com> <20070222074044.GA4158@elte.hu> <20070228094522.GA17716@elte.hu> <20070228202156.GA15846@elte.hu> X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1918 Lines: 55 On Wed, 28 Feb 2007, Ingo Molnar wrote: > > * 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 Did you hide all the complexity of the userspace atom decoding inside another function? :) How much code would go away, in case we pick a simple/parallel sys_async_exec engine? Atoms decoding, special userspace variable access for loops, jumps/cond/... VM engine. > 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. Wouldn't you agree on a simple/parallel execution engine like me and Linus are proposing (and threadlets, of course)? - Davide - 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/