Messages in this thread | | | Date | Fri, 24 Mar 2017 22:31:46 -0400 | From | Steven Rostedt <> | Subject | Re: [RFC v5 2/9] sched/deadline: improve the tracking of active utilization |
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On Fri, 24 Mar 2017 22:47:15 +0100 luca abeni <luca.abeni@santannapisa.it> wrote:
> Ok... Since I am not good at ascii art, would it be ok to add a textual > description? If yes, I'll add a comment like: > " > The utilization of a task is added to the runqueue's active utilization > when the task becomes active (is enqueued in the runqueue), and is > removed when the task becomes inactive. A task does not become > immediately inactive when it blocks, but becomes inactive at the so > called "0 lag time"; so, we setup the "inactive timer" to fire at the > "0 lag time". When the "inactive timer" fires, the task utilization is > removed from the runqueue's active utilization. If the task wakes up > again on the same runqueue before the "0 lag time", the active > utilization must not be changed and the "inactive timer" must be > cancelled. If the task wakes up again on a different runqueue before > the "0 lag time", then the task's utilization must be removed from the > previous runqueue's active utilization and must be added to the new > runqueue's active utilization. > In order to avoid races between a task waking up on a runqueue while the > "inactive timer" is running on a different CPU, the "dl_non_contending" > flag is used to indicate that a task is not on a runqueue but is active > (so, the flag is set when the task blocks and is cleared when the > "inactive timer" fires or when the task wakes up).
Sure, the above is great if you never want anyone to read it ;)
Can you please break it up a little. My head starts to spin by the third line down.
-- Steve
> " > (if this is ok, where can I add this comment?)
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