Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265635AbTFRX6x (ORCPT ); Wed, 18 Jun 2003 19:58:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265637AbTFRX6x (ORCPT ); Wed, 18 Jun 2003 19:58:53 -0400 Received: from fed1mtao06.cox.net ([68.6.19.125]:21752 "EHLO fed1mtao06.cox.net") by vger.kernel.org with ESMTP id S265635AbTFRX6v (ORCPT ); Wed, 18 Jun 2003 19:58:51 -0400 Message-ID: <3EF10002.7020308@cox.net> Date: Wed, 18 Jun 2003 17:12:50 -0700 From: "Kevin P. Fleming" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5a) Gecko/20030603 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Greg KH CC: Oliver Neukum , Robert Love , Patrick Mochel , Andrew Morton , sdake@mvista.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] udev enhancements to use kernel event queue References: <3EE8D038.7090600@mvista.com> <1055459762.662.336.camel@localhost> <20030612232523.GA1917@kroah.com> <200306132201.47346.oliver@neukum.org> <20030618225913.GB2413@kroah.com> In-Reply-To: <20030618225913.GB2413@kroah.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1090 Lines: 25 Greg KH wrote: >>If this kmalloc fails, you'll have a hole in the numbers and >>user space will be very confused. You need to report dropped >>events if you do this. > > > Yes, we should add the sequence number last. > While this is not a bad idea, I don't think you want to make a promise to userspace that there will never be gaps in the sequence numbers. When this sequence number was proposed, in my mind it seemed perfect because then userspace could _order_ multiple events for the same device to ensure they got processed in the correct order. I don't know that any hotplug userspace implementation is going to be large and complex enough to warrant "holding" events until lower-numbered events have been delivered. That just seems like a very difficult task with little potential gain, but I could very well be mistaken :-) - 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/