Re: [PATCH bpf-next v4 0/4] XDP: Support atomic replacement of XDP interface attachments

On Wed, Mar 25, 2020 at 06:23:25PM +0100, Toke Høiland-Jørgensen wrote:

This series adds support for atomically replacing the XDP program loaded on an
interface. This is achieved by means of a new netlink attribute that can specify
the expected previous program to replace on the interface. If set, the kernel
will compare this "expected id" attribute with the program currently loaded on
the interface, and reject the operation if it does not match.

With this primitive, userspace applications can avoid stepping on each other's
toes when simultaneously updating the loaded XDP program.

Changelog:

v4:
- Switch back to passing FD instead of ID (Andrii)
- Rename flag to XDP_FLAGS_REPLACE (for consistency with other similar uses)

please stop resending the set without concluding the previous three! discussion threads.
It's already hard enough for people to follow.