On Wed, 4 May 2016 15:34:21 -0700 Andrey Vagin <ava...@openvz.org> wrote:
> Hi Stephen, > > On Wed, May 4, 2016 at 1:22 PM, Stephen Hemminger > <step...@networkplumber.org> wrote: > > I understand how reading /proc or /sys can be a bottleneck, but this > > proposed method using a system call is the wrong way to do this. > > > > Why not use netlink like other systems do which allows a message > > based response which allows for future changes (no fixed datastructures), > > and is message based. > > > > Generic netlink has already been used by several other subsystems. > > I used netlink in two first versions of task_diag, but then Andy > convinced me that netlink interfaces are not ideal for this case. I > added him into Cс. > > Here is a thread with our discussion about using netlink for > task_diag: https://lkml.org/lkml/2015/12/15/520 > Can I ask you to read it and give your comments? It would be nice to > find a way how to use netlink sockets instead of creating a new > interface. > > Thanks, > Andrew LKML is too busy, no one reads it anymore :-) Since this is netlink related you need to discuss it on netdev. The objection seems to be time or creation versus time of use and permissions. Netlink internally is not really message based all responses are generated in the context of the send(). You need credentials to create the socket, but the actual response will occur in the context of the calling process. I don't see how that is substantially different than a system call.
