Hello, On Mon, 26 Oct 2020, Cezar Sá Espinola wrote: > Hi all. This is my first message here and also my first attempt at kernel > development so I'm a bit nervous and afraid I'm doing something wrong. > > The last few days I've been toying with a patch to IPVS to allow me to use > netlink to dump all services and all its destinations in a single call. > > The motivation for this came after profiling a kubernetes node machine with a > few thousand IPVS services each with an average of two destinations. The > component responsible for ensuring that the IPVS rules are correct always needs > a fresh dump of all services with all destinations and currently this is > accomplished by issuing a IPVS_CMD_GET_SERVICE generic netlink dump command > followed by multiple IPVS_CMD_GET_DEST dump commands. This is how ipvsadm -S runs now, list_all() gets all services and for each gets its destinations. > The patch in question adds a new netlink command IPVS_CMD_GET_SERVICE_DEST > which dumps all services where each service is followed by a dump of its > destinations. It's working now on my machine and some preliminary experiments > show me that there's a significant performance improvement in switching to a > single call to dump everything. However, I have some questions that I'd like to > talk about before trying to submit it. > > 1. First of all is such a patch adding a new command something desirable and > could it possibly be merged or should I just drop it? It depends on its complexity, are you changing the ipvsadm -S code or just the kernel part? > 2. I can see that besides the generic netlink interface there's also another > interface based on getsockopt options, should the patch also add a new socket > option or is it okay for this new functionality to be exclusive to generic > netlink? No, sockopt is old interface and it is not changed, it lacks IPv6 support, etc. > 3. Should this go forward, any advice on my next steps? Should I simply send the > patch here? You can post it with [PATCH RFC] tag, so that we can see how do you mix services and destinations in same packet. You can also add speed comparison after the --- line for more information. Regards -- Julian Anastasov <ja@xxxxxx>
