[PATCH v2 4/5] riscv: add lazy preempt support

Mon Sep 5 01:46:41 PDT 2022

On 2022-09-05 16:33:54 [+0800], Guo Ren wrote:
> > There is "generic" code in the PREEMPT_RT patch doing that. The counter
> > is incremented/ decremented via preempt_lazy_enable()/disable() and one
> > of the user is migrate_disable()/enable().
> > Basically if a task is task_is_realtime() then NEED_RESCHED is set for
> > the wakeup. For the remaining states (SCHED_OTHER, …) NEED_RESCHED_LAZY
> > is set for the wakeup. This can be delayed if the task is in a "preempt
> > disable lazy" section (similar to a preempt_disable() section) but a
> > task_is_realtime() can still be scheduled if needed.
> Okay, It should be [PATCH RT]. RISC-V would also move to GENERIC_ENTRY
> [1], so above assembly code would be replaced by generic one, right?

correct.

Sebastian