Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755872AbXIDWpD (ORCPT ); Tue, 4 Sep 2007 18:45:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754341AbXIDWoy (ORCPT ); Tue, 4 Sep 2007 18:44:54 -0400 Received: from x35.xmailserver.org ([64.71.152.41]:2165 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754336AbXIDWox (ORCPT ); Tue, 4 Sep 2007 18:44:53 -0400 X-AuthUser: davidel@xmailserver.org Date: Tue, 4 Sep 2007 15:44:49 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Michael Kerrisk cc: Andrew Morton , corbet@lwn.net, jengelh@computergmbh.de, hch@lst.de, stable@kernel.org, Ulrich Drepper , Linus Torvalds , Linux Kernel Mailing List , tglx@linutronix.de, rdunlap@xenotime.net Subject: Re: [PATCH] Revised timerfd() interface In-Reply-To: <20070904204932.208520@gmx.net> Message-ID: References: <20070825064114.107820@gmx.net> <46DD116C.4040301@gmx.net> <20070904011800.762523a4.akpm@linux-foundation.org> <20070904204932.208520@gmx.net> 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: 1469 Lines: 36 On Tue, 4 Sep 2007, Michael Kerrisk wrote: > > Useless like it'd be a motorcycle w/out a cup-holder :) > > Seriously, the ability to get the previous values from "something" could > > have a meaning if this something is a shared global resource (like > > signals > > for example). In the timerfd case this makes little sense, since you can > > create as many timerfd as you like and you do not need to share a single > > one by changing/restoring the original context. > > Davide, > > As I think about this more, I see more problems with > your argument. timerfd needs the ability to get and > get-while-setting just as much as the earlier APIs. > Consider a library that creates a timerfd file descriptor that > is handed off to an application: that library may want > to modify the timer settings without having to create a > new file descriptor (the app mey not be able to be told about > the new fd). Your argument just doesn't hold, AFAICS. Such hypotethical library, in case it really wanted to offer such functionality, could simply return an handle instead of the raw fd, and take care of all that stuff in userspace. Again, mimicking POSIX APIs doesn't always take you in the right place. - 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/