Re: [PATCH V2 1/1] tick: broadcast-hrtimer: Fix a race in bc_set_next

From: Thomas Gleixner
Date: Thu Sep 26 2019 - 06:02:29 EST


On Wed, 25 Sep 2019, Balasubramani Vivekanandan wrote:
>
> Since it is now allowed to start the hrtimer from the callback, there is

Is now allowed?

> no need for the try to cancel logic. All that is now removed.

Sure I can see that it is removed from the patch, but why and why is it
correct?

> [1]: rcu stall warnings noticed before this patch
>
> [ 26.477514] INFO: rcu_preempt detected stalls on CPUs/tasks:

<SNIP>

I which way is this backtrace giving any useful information about the
problem?

>
> Signed-off-by: Balasubramani Vivekanandan <balasubramani_vivekanandan@xxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Interesting. You claim authorship on that patch and then you put my SOB
after yours just because you feel entitled to do so?

I surely appreciate the time you spent to analyze the problem and I
wouldn't have said anything if you just would have done the right thing:

1) Write a changelog which explains why the change is actually correct

2) Not wreckage the formatting which I intentionally did for readability
sake

3) Add 'Originally-by: Thomas Gleixner' or at least having the courtesy to
mention that this is not your work.

Thanks,

tglx