Re: [PATCH v4 09/26] sched/deadline: Reset the deadline and the runtime with the parameters

[Mathieu Desnoyers]

On 2026-11-06 21:18, sashiko-bot@xxxxxxxxxx wrote:
> unreset donor period in switched_from_dl() when dl_runtime != 0

replenish_dl_entity() does not take the donor's period at the boost
here: dl_deadline is not 0. The donor's values come at a refill or a
wakeup during the boost. At the deboost, task_non_contending() keeps
them only if the 0-lag time is ahead. That means the runtime left fits
the task's own bandwidth until that deadline. Otherwise the bandwidth
goes, with the parameters, the deadline and the runtime. So a task that
comes back with the same parameters runs no more than its own
bandwidth. The release time is the same question as on patch 10.

> donor deadline and runtime kept on deboost after setattr

Right. A task that stays in the class at its deboost keeps what the
donor left. A deadline task boosted by an earlier waiter does the same
upstream, since 2d3d891d3344. v5 adds a patch after this one. It resets
the deadline and the runtime when a boost ends in the class with a
runtime above the task's own. It also adds a selftest case.

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com