Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751508AbXE2WRh (ORCPT ); Tue, 29 May 2007 18:17:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750808AbXE2WRb (ORCPT ); Tue, 29 May 2007 18:17:31 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:57145 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750803AbXE2WRa (ORCPT ); Tue, 29 May 2007 18:17:30 -0400 Message-ID: <465CA654.5000505@garzik.org> Date: Tue, 29 May 2007 18:16:52 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Zach Brown CC: linux-kernel@vger.kernel.org, Ingo Molnar , Linus Torvalds , Arjan van de Ven , Christoph Hellwig , Andrew Morton , Alan Cox , Ulrich Drepper , Evgeniy Polyakov , "David S. Miller" , Suparna Bhattacharya , Davide Libenzi , Jens Axboe , Thomas Gleixner Subject: Re: Syslets, Threadlets, generic AIO support, v6 References: <20070529212718.GH7875@mami.zabbo.net> In-Reply-To: <20070529212718.GH7875@mami.zabbo.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.8 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2474 Lines: 59 Zach Brown wrote: > I'm pleased to announce the availability of version 6 of the syslet subsystem. > Ingo and I agreed that I'll handle syslet releases while he's busy with CFS. I > copied the cc: list from Ingo's v5 announcement. If you'd like to be dropped > (or added), please let me know. > > The v6 patch series against 2.6.21 can be downloaded from: > > http://oss.oracle.com/~zab/syslets/v6/ > > Example applications and previous syslet releases can be found at: > > http://people.redhat.com/~mingo/syslet-patches/ > > The syslet subsystem aims to provide user-space with an efficient interface for > managing the asynchronus submission and completion of existing system calls. > > The only changes since v5 are small changes that I made to support the > experimental aio patch described below. > > My syslet subsystem todo list is as follows, in no particular order: > > - replace WARN_ON() calls with error handling or avoidance > - split the x86_64-async.patch into more specific patches > - investigate integration with ptrace > - investigate rare ./syslet-test cpu spinning > - provide distro kernel rpms and documentation for developers > - compat design problems, still? http://lkml.org/lkml/2007/3/7/523 > > Included in this patch series is an experimental patch which reworks fs/aio.c > to reuse the syslet subsystem to process iocb requests from user space. The > intent of this work is to simplify the code and broaden aio functionality. > > Many issues need to be addressed before this aio work could be merged: > > - support cancellation by sending signals to async_threads > - figure out what to do about signals from handlers, like SIGXFSZ > - verify that heavy loads do not consume excessive cpu or memory > - concurrent dio writes > - cfq gets confused, share io_context amongst threads? > - restrict allowed operations like .aio_{r,w} methods used to > > More details on this work in progress can be found in the patch. > > Any and all feedback is welcome and encouraged! You should pick up the kevent work :) Having async request and response rings would be quite useful, and most closely match what is going on under the hood in the kernel and hardware. Jeff - 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/