Re: [PATCH 3/3] kernel/smp: add more data to CSD lock debugging

[Peter Zijlstra]

On Sun, Feb 28, 2021 at 04:07:04PM -0800, Paul E. McKenney wrote:
> On Fri, Feb 26, 2021 at 10:05:51PM +0100, Peter Zijlstra wrote:
> > On Fri, Feb 26, 2021 at 10:12:05AM -0800, Paul E. McKenney wrote:
> > > On Fri, Feb 26, 2021 at 05:38:44PM +0100, Peter Zijlstra wrote:
> > > > 
> > > > I hate all of this, but if this will finally catch the actual problem,
> > > > we can then revert all this, so sure.
> > > 
> > > OK, I will bite...  What exactly do you hate about it?
> > 
> > It's ugly and messy. We're basically commiting a debug session. Normally
> > gunk like this is done in private trees, then we find the problem and
> > fix that and crap like this never sees the light of day.
> 
> Is your hatred due to the presence of debug code at all, or a belief that
> this code is unlikely to be useful in any subsequent IPI-related bug hunt?

The clutter, mostly I think. There's a lot of debug sprinkled about.