On 4/29/19 4:52 PM, Vinicius Costa Gomes wrote:

This allows for a new schedule to be specified during runtime, without
removing the current one.

For that, the semantics of the 'tc qdisc change' operation in the
context of taprio is that if "change" is called and there is a running
schedule, a new schedule is created and the base-time (let's call it
X) of this new schedule is used so at instant X, it becomes the
"current" schedule. So, in short, "change" doesn't change the current
schedule, it creates a new one and sets it up to it becomes the
current one at some point.

In IEEE 802.1Q terms, it means that we have support for the
"Oper" (current and read-only) and "Admin" (future and mutable)
schedules.

...

It was necessary to fix a bug, so the clockid doesn't need to be
specified when changing the schedule.

Does that bug fix need to be applied to master?

Most of the changes are related to make it easier to reuse the same
function for printing the "admin" and "oper" schedules.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 tc/q_taprio.c | 42 +++++++++++++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 9 deletions(-)

applied to iproute2-next.