Re: 答复: 答复: 答复: [PATCH] kdb: Fix the deadlock issue in KDB debugging.

Daniel Thompson
2024-03-12T10:24:23Z

On Tue, Mar 12, 2024 at 10:04:54AM +0000, Liuye wrote:
> >On Tue, Mar 12, 2024 at 08:37:11AM +0000, Liuye wrote:
> >> I know that you said schedule_work is not NMI save, which is the first
> >> issue. Perhaps it can be fixed using irq_work_queue. But even if
> >> irq_work_queue is used to implement it, there will still be a deadlock
> >> problem because slave cpu1 still has not released the running queue
> >> lock of master CPU0.
> >
> >This doesn't sound right to me. Why do you think CPU1 won't release
> >the run queue lock?
>
> In this example, CPU1 is waiting for CPU0 to release dbg_slave_lock.

That shouldn't be a problem. CPU0 will have released that lock by
the time the irq work is dispatched.

Daniel.