On 03/12, Leon Romanovsky wrote: > On Wed, Mar 12, 2025 at 04:20:08PM +0200, Nikolay Aleksandrov wrote: > > On 3/12/25 1:29 PM, Leon Romanovsky wrote: > > > On Wed, Mar 12, 2025 at 11:40:05AM +0200, Nikolay Aleksandrov wrote: > > >> On 3/8/25 8:46 PM, Leon Romanovsky wrote: > > >>> On Fri, Mar 07, 2025 at 01:01:50AM +0200, Nikolay Aleksandrov wrote: > > [snip] > > >> Also we have the ephemeral PDC connections>> that come and go as > > needed. There more such objects coming with more > > >> state, configuration and lifecycle management. That is why we added a > > >> separate netlink family to cleanly manage them without trying to fit > > >> a square peg in a round hole so to speak. > > > > > > Yeah, I saw that you are planning to use netlink to manage objects, > > > which is very questionable. It is slow, unreliable, requires sockets, > > > needs more parsing logic e.t.c > > > > > > To avoid all this overhead, RDMA uses netlink-like ioctl calls, which > > > fits better for object configurations. > > > > > > Thanks > > > > We'd definitely like to keep using netlink for control path object > > management. Also please note we're talking about genetlink family. It is > > fast and reliable enough for us, very easily extensible, > > has a nice precise object definition with policies to enforce various > > limitations, has extensive tooling (e.g. ynl), communication can be > > monitored in realtime for debugging (e.g. nlmon), has a nice human > > readable error reporting, gives the ability to easily dump large object > > groups with filters applied, YAML family definitions and so on. > > Having sockets or parsing are not issues. > > Of course it is issue as netlink relies on Netlink sockets, which means > that you constantly move your configuration data instead of doing > standard to whole linux kernel pattern of allocating configuration > structs in user-space and just providing pointer to that through ioctl > call. And you still call copy_from_user on that user-space pointer. So how is it an improvement over netlink? netlink is just a flexible tlv, if you don't like read/write calls, we can add netlink_ioctl with a pointer to netlink message...
