Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751531AbWJEJCr (ORCPT ); Thu, 5 Oct 2006 05:02:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751527AbWJEJCr (ORCPT ); Thu, 5 Oct 2006 05:02:47 -0400 Received: from relay.2ka.mipt.ru ([194.85.82.65]:64434 "EHLO 2ka.mipt.ru") by vger.kernel.org with ESMTP id S1751258AbWJEJCq (ORCPT ); Thu, 5 Oct 2006 05:02:46 -0400 Date: Thu, 5 Oct 2006 13:02:15 +0400 From: Evgeniy Polyakov To: Ulrich Drepper Cc: Ulrich Drepper , lkml , David Miller , Andrew Morton , netdev , Zach Brown , Christoph Hellwig , Chase Venters Subject: Re: [take19 0/4] kevent: Generic event handling mechanism. Message-ID: <20061005090214.GB1015@2ka.mipt.ru> References: <115a6230591036@2ka.mipt.ru> <11587449471424@2ka.mipt.ru> <20060927150957.GA18116@2ka.mipt.ru> <20061004045527.GB32267@2ka.mipt.ru> <452363C5.1020505@redhat.com> <20061004074821.GA22688@2ka.mipt.ru> <4523ED6C.9080902@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4523ED6C.9080902@redhat.com> User-Agent: Mutt/1.5.9i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.7.5 (2ka.mipt.ru [0.0.0.0]); Thu, 05 Oct 2006 13:02:15 +0400 (MSD) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2115 Lines: 54 On Wed, Oct 04, 2006 at 10:20:44AM -0700, Ulrich Drepper (drepper@redhat.com) wrote: > Evgeniy Polyakov wrote: > > It is completely possible to do what you describe without special > > syscall parameters. > > First of all, I don't see how this is efficiently possible. The mask > might change from call to call. And you can add/remove signal events using existing kevent api between calls. > Second, hasn't it sunk in that inventing new ways to pass parameters is > bad? Programmers don't want to learn new ways for every new interface. > Reuse is good! And creating special cases for usual events is bad. There is unified way to deal with events in kevent - add/remove/modify/wait on them, signals are just usual events. > This applies to the signal mask here. > > But there is another parameter falling into that category and I meant to > mention it before: the timeout value. All other calls except poll and > especially all modern interfaces use a timespec pointer. This is the > way times are kept in userland code. Don't try to force people to do > something else. > > Using a timespec also has the advantage that we can add an absolute > timeout value mode (optional) instead of the relative timeout value. > > In this context, we should/must be able to specify which clock the > timeout is for (not as part of the wait call, but another control > operation perhaps). It's important to distinguish between > CLOCK_REALTIME and CLOCK_MONOTONE. Both have their use. I think you wanted to say, that 'all event mechanism except the most commonly used poll/select/epoll use timespec'. I designed it to be similar to poll(), it is really good interface. Nature of the waiting is to wait for some time, so I put there that 'some time'. > -- > ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖ > -- Evgeniy Polyakov - 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/