Re: [PATCH linux-5.2.y-rt only] hrtimer: correct the logic for grab expiry lock

[Zhantao Tang]

在 2020/8/12 下午7:45, Rasmus Villemoes 写道:
> On 12/08/2020 12.50, zhantao.tang@xxxxxxxxxxxxx wrote:
> > From: Zhantao Tang <zhantao.tang@xxxxxxxxxxxxx>
> >
> > In commit: 47b6de0b7f22 ("hrtimer: Add a missing bracket and hide `migration_base' on !SMP")
> > a inline function is_migration_base() is introduced. But
> > the logic of the hrtimer_grab_expiry_lock was changed.
> >
> > This patch is to correct it.
> Yup, same patch sent back in April, which also had a fixes tag for 5.2.
>
> https://lore.kernel.org/lkml/20200428144026.5882-1-rasmus.villemoes@xxxxxxxxx/
>
> It got picked up for 4.19-rt, dunno why it wasn't for 5.2-rt.

Yes， currently 5.2 rt kernel not fix the issue.

And I checked the 4.19 rt kernel, but  did not find the implementation 
of hrtimer_grab_expiry_lock().

It used hrtimer_wait_for_timer() and the logic is OK.


Thanks,

Zhantao

> Rasmus