From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Stezenbach Date: Wed, 09 Dec 2009 21:03:03 +0000 Subject: Re: Q: netdev: generate kobject uevent on network events. Message-Id: <20091209210303.GA24522@sig21.net> List-Id: References: <20091209170251.GA11650@sig21.net> <1260386486.28042.6.camel@localhost.localdomain> In-Reply-To: <1260386486.28042.6.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Williams Cc: Kay Sievers , Stephen Hemminger , netdev@vger.kernel.org, linux-hotplug@vger.kernel.org On Wed, Dec 09, 2009 at 11:21:26AM -0800, Dan Williams wrote: > On Wed, 2009-12-09 at 19:46 +0100, Kay Sievers wrote: > > > > Can't, in some setups, these events happen at a rather high frequency? > > I heard of people running many hundreds of ppp interfaces on a single > > box acting as a DSL concentrator. They state to already have trouble > > handling the amount of uevents generated on such boxes just for the > > "add/remove" events of all the interfaces if something goes wrong with > > the network. If we add more for state transitions, such events would > > probably need to be rate-limited. In general, uevents/udev are not > > really suitable for high-frequency events, and if such behavior can be > > expected, we might better stick with the current netlink interface. > > And then lets direct energy towards making the netlink interface simpler > for app writers. Either by fixing up libnl to be dead-simple to use, or > some other mechanism. Let's fix the *actual* problem (netlink is hard > to use from shell scripts) instead of creating more interfaces that work > around it. Or maybe shellscripts are simply the wrong tool for this > job? Hm, yeah, I liked the simplicity of the uevent patch, but I see it doesn't work for everyone. BTW, I just saw that a current busybox version (1.15+) has an iflugd applet, which uses a mix of (open coded) netlink and polling via various socket ioctls. http://git.busybox.net/busybox/tree/networking/ifplugd.c Thanks, Johannes