Re: [PATCH v2, RESEND] sched/rt: Try to restart rt period timer when rt runtime exceeded

[Lihua (lihua, ran)]

在 2021/12/3 15:17, Greg KH 写道:
> On Fri, Dec 03, 2021 at 03:36:18AM +0000, Li Hua wrote:
> > When rt_runtime is modified from -1 to a valid control value, it may
> > cause the task to be throttled all the time. Operations like the following
> > will trigger the bug. E.g:
> > 1. echo -1 > /proc/sys/kernel/sched_rt_runtime_us
> > 2. Run a FIFO task named A that executes while(1)
> > 3. echo 950000 > /proc/sys/kernel/sched_rt_runtime_us
> >
> > When rt_runtime is -1, The rt period timer will not be activated when task
> > A enqueued. And then the task will be throttled after setting rt_runtime to
> > 950,000. The task will always be throttled because the rt period timer is
> > not activated.
> >
> > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > Signed-off-by: Li Hua <hucool.lihua@xxxxxxxxxx>
> > ---
> > v1->v2:
> >    - call do_start_rt_bandwidth to reduce repetitive code.
> >    - use raw_spin_lock_irqsave to avoid deadlock on a timer context.
> > ---
> >   kernel/sched/rt.c | 23 ++++++++++++++++++-----
> >   1 file changed, 18 insertions(+), 5 deletions(-)
> <formletter>
>
> This is not the correct way to submit patches for inclusion in the
> stable kernel tree.  Please read:
>      https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> for how to do this properly.
I did not CC: stable in the signed-off region，Is that so？
> </formletter>
> .