From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Date: Tue, 18 Oct 2005 01:06:40 +0000 Subject: Re: synchronization (or lack thereof) for uevents Message-Id: <20051018010640.GB2817@vrfy.org> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org On Mon, Oct 17, 2005 at 11:26:21AM -0400, goggin, edward wrote: > Is it possible to ignore a hotplug event and deal only with the associated > uevent? > > It seems that the asynchronous nature of uevents, (that is, they are sent to > a netlink > socket as datagrams -- therefore without a reply acknowledgement), makes it > difficult > to reliably act upon one when it is possible that multiple, related uevents, > which although > being sent later, may affect the servicing of the current one. I don't really get it. /sbin/hotplug events and netlink uevents are carrying the same content and fired at the same time. Both have the same SEQNUM and the same keys. Netlink uevents are a complete replacement for /sbin/hotplug. What would an ack for the uevent be good for. These events are sent to the socket buffer and reliable as long as they fit into the buffer. The current udev has a buffer of 16MB which can carry app. 50.000 events if udevd is not reading anything. udevd reads the events and excutes them in parallel anyway. This is intentional and there is no need or it would make sense to serialize events besides events for the same device or a child device still running. What is _exactly_ your problem? Kay ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel