From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755503AbZAaTIw (ORCPT ); Sat, 31 Jan 2009 14:08:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751430AbZAaTIn (ORCPT ); Sat, 31 Jan 2009 14:08:43 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:56539 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751896AbZAaTIm (ORCPT ); Sat, 31 Jan 2009 14:08:42 -0500 X-AuthUser: davidel@xmailserver.org Date: Sat, 31 Jan 2009 11:08:40 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: wli@movementarian.org cc: Linus Torvalds , Linux Kernel Mailing List , Andrew Morton , Alan Cox , Ingo Molnar , David Miller Subject: Re: [patch 3/7] epoll keyed wakeups - introduce key-aware wakeup macros In-Reply-To: <20090131045733.GA26410@movementarian.org> Message-ID: References: <20090131045733.GA26410@movementarian.org> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 30 Jan 2009, wli@movementarian.org wrote: > On Fri, Jan 30, 2009 at 07:49:26PM -0800, Linus Torvalds wrote: > > But even more I dislike the notion of this being a "key". It's not. It's > > about poll events, nothing more. So renaming it to "_key()" in no way > > helps. > > Yes, _internally_ we send that "void *key" around, and then leave it to > > lower levels to agree about how it is used, but at the level _you_ then > > use it, that is no longer the case. When you do a > > kwake_up_interruptible(&tty->write_wait, POLLOUT); > > that has _nothing_ to do with "keys" any more. So the 'k' prefix is wrong > > and really odd-looking, but a '_key' postfix wouldn't be much better > > either. Because when you pass in POLLOUT, you're not using it as a key, > > you are very much using it as a poll-specific thing. > > So the naming should match that. I suspect a '_poll' postfix (or a 'poll_' > > prefix would work and make sense. > > The filtered wakeup code uses some notion of a key already. There, the > key is to route wakeups to recipients associated with the correct > object. Here, the objects are known in advance. The wakeup is to give > them some particular message in which they may not necessarily be > interested. Names indicative of that (e.g. *_msg/msg_*) would clarify > the distinction between it and the filtered wakeup code used for pages. I had thought of giving the void* some structure, besides being a cast from an event mask, so that later on we'd be able to eventually embed more information in the wakeup. Dunno if worth it. - Davide