Re: [PATCH v3] sched/fair: Add advisory flag for borrowing a timeslice (was: Pre-emption control for userspace)

From: Srikar Dronamraju
Date: Tue Nov 25 2014 - 05:13:10 EST


>
> - Request to borrow timeslice is not guranteed to be honored.
> - If the task is allowed to borrow, kernel will inform the task
> of this. When this happens, task must yield the processor as soon
> as it completes its critical section.
> - If the task fails to yield processor after being allowed to
> borrow, it is penalized by forcing it to skip its next time slot
> by the scheduler.
> - Task is charged additional time for the borrowed timeslice as
> accumulated run time. This pushes it further down in consideration
> for the next task to run.
>

Is there a way for us to identify if the lock is contended?
Because it may not be prudent to allow a task to borrow timeslice for a
lock which isnt contended.

--
Thanks and Regards
Srikar Dronamraju

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