Re: [PATCH] cgroup: drop unneeded semicolon

[Tejun Heo <tj@kernel.org>]

Hello,

On Sat, Aug 01, 2026 at 07:37:13PM -0400, Waiman Long wrote:
> > diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
> > index 38f8d9df8..f87fc4550 100644
> > --- a/kernel/cgroup/cgroup.c
> > +++ b/kernel/cgroup/cgroup.c
> > @@ -104,7 +104,7 @@ DEFINE_PERCPU_RWSEM(cgroup_threadgroup_rwsem);
> >   #define cgroup_assert_mutex_or_rcu_locked()				\
> >   	RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&			\
> >   			   !lockdep_is_held(&cgroup_mutex),		\
> > -			   "cgroup_mutex or RCU read lock required");
> > +			   "cgroup_mutex or RCU read lock required")
> >   /*
> >    * cgroup destruction makes heavy use of work items and there can be a lot
> > 
> The RCU_LOCKDEP_WARN() macro is basically a "do { ...} while (0...)"
> statement. It doesn't have a ';' at the end.  So your commit log isn't
> right.
> 
> An additional semicolon at the end doesn't harm. By removing the semicolon,
> even if not needed, may make people wonder if it is right when reading the
> code wasting their time to figure out if it is all right. So I don't see any
> advantage in removing it.

I think the extra semicolon can hurt. Imagine something like this:

        if (blah)
                cgroup_assert_mutex_or_rcu_locked();
        else
                something else;

This should work but with the extra semicolon, it doesn't. I don't see why
we wouldn't fix this. It's obviously wrong.

Thanks.

-- 
tejun