From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767484AbXCIUWa (ORCPT ); Fri, 9 Mar 2007 15:22:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767485AbXCIUWa (ORCPT ); Fri, 9 Mar 2007 15:22:30 -0500 Received: from an-out-0708.google.com ([209.85.132.248]:48964 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767484AbXCIUW2 (ORCPT ); Fri, 9 Mar 2007 15:22:28 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=JTgJdedyNp0RkHo+AHHjnAw6OXpoJDZowKiNe/M6NQn9OenbtZyXB0+wEedPiceaGsfNMd7bYLYFrGn2O3bfp4VD2dcaWyfdCBvokW0MF/lC7EnPAtVhyni3FcDDjOIWOxKB/gorGawOdjYx3fMhdPBl4obxzrYdVjVvXY+D0kQ= Message-ID: <6f703f960703091222w512af954s7cf245b02d78d1bd@mail.gmail.com> Date: Fri, 9 Mar 2007 11:22:27 -0900 From: "Kent Overstreet" To: "Linus Torvalds" Subject: Re: [patch 2/5] signalfd v2 - signalfd core ... Cc: "Davide Libenzi" , "David M. Lloyd" , "Linux Kernel Mailing List" , "Andrew Morton" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1173364264.6891.3.camel@localhost> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 3/8/07, Linus Torvalds wrote: > Which is why you introduced a new system call, but that leads to all the > problems with the file descriptor no longer being *usable*. > > Think scripts. It's easy to do reads in perl scripts, and parse the > output. In contrast, making perl use a new system call is quite > challenging. If you're going to allow reads from the fd, then it makes sense to let processes get the fd by opening a file; if you've got to call siginfo_create() or what have you, the fact that you can do reads isn't terribly useful to perl or what have you. Inotify even makes you get events with read() today; but you have to use system calls to get the fd and to send events (inotify_add_watch, inotify_rm_watch), which is something I've never understood. It would, to me, be very cool if everything that was a stream of bytes really was a file; this is something I've always thought plan 9 got very right. Epoll and inotify could work this way, and I'm sure there's others I'm forgetting. If people are interested in this sort of thing, I'll start working on a patch. Are there any thoughts on where these sorts of pseudodevices should be these days?