Re: [PATCH] srcu: remove never used variable

From: Paul E. McKenney
Date: Thu Feb 22 2018 - 20:20:45 EST


On Fri, Feb 23, 2018 at 09:04:05AM +0800, Zhouyi Zhou wrote:
> Thanks Paul for reviewing

And thank you for your interest in SRCU! I am pretty sure that other
bugs still remain. ;-)

Thanx, Paul

> Cheers
> Zhouyi
>
> On Friday, February 23, 2018, Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> wrote:
>
> > On Thu, Feb 22, 2018 at 06:52:37AM +0000, zhouzhouyi@xxxxxxxxx wrote:
> > > From: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
> > >
> > > In function srcu_gp_end, the variable idxnext is never used after assign,
> > > remove it and its assign statement.
> > >
> > > Signed-off-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
> >
> > Good catch, but Byungchul Park beat you to it. Please see commit
> > a72da917f186 ("srcu: Remove dead code in srcu_gp_end()") in -rcu.
> >
> > Thanx, Paul
> >
> > > ---
> > > kernel/rcu/srcutree.c | 2 --
> > > 1 file changed, 2 deletions(-)
> > >
> > > diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
> > > index d5cea81..1241715 100644
> > > --- a/kernel/rcu/srcutree.c
> > > +++ b/kernel/rcu/srcutree.c
> > > @@ -531,7 +531,6 @@ static void srcu_gp_end(struct srcu_struct *sp)
> > > unsigned long flags;
> > > unsigned long gpseq;
> > > int idx;
> > > - int idxnext;
> > > unsigned long mask;
> > > struct srcu_data *sdp;
> > > struct srcu_node *snp;
> > > @@ -555,7 +554,6 @@ static void srcu_gp_end(struct srcu_struct *sp)
> > >
> > > /* Initiate callback invocation as needed. */
> > > idx = rcu_seq_ctr(gpseq) % ARRAY_SIZE(snp->srcu_have_cbs);
> > > - idxnext = (idx + 1) % ARRAY_SIZE(snp->srcu_have_cbs);
> > > rcu_for_each_node_breadth_first(sp, snp) {
> > > spin_lock_irq_rcu_node(snp);
> > > cbs = false;
> > > --
> > > 2.1.4
> > >
> >
> >