Re: [PATCH] srcu: Fix incorrect condition in srcu_funnel_exp_start()

[Byungchul Park]

On 2/15/2018 6:42 AM, Paul E. McKenney wrote:
> On Wed, Feb 14, 2018 at 05:59:54PM +0900, Byungchul Park wrote:
> > We should've kept sp->srcu_gp_seq_needed_exp the furthest. But
> > it probably fails because of the incorrect condition. Fix it.
> >
> > Signed-off-by: Byungchul Park <byungchul.park@xxxxxxx>
>
> Good catch, and thank you for reviewing the SRCU code, but Ildar Ismagilov
> beat you to this one.  Please see 574428dee1f3 ("rcu: Fix misprint in
> srcu_funnel_exp_start") in -rcu.

Hi Paul,

I'm sorry I'm late. It's been Lunar New Year holiday since last
thursday.

Do you mean:

git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git

Is this rcu's main dev-tree?

Thanks for replying anyway, and happy new year~

> 							Thanx, Paul
>
> > ---
> >   kernel/rcu/srcutree.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
> > index d5cea81..44bc0fa 100644
> > --- a/kernel/rcu/srcutree.c
> > +++ b/kernel/rcu/srcutree.c
> > @@ -626,7 +626,7 @@ static void srcu_funnel_exp_start(struct srcu_struct *sp, struct srcu_node *snp,
> >   		spin_unlock_irqrestore_rcu_node(snp, flags);
> >   	}
> >   	spin_lock_irqsave_rcu_node(sp, flags);
> > -	if (!ULONG_CMP_LT(sp->srcu_gp_seq_needed_exp, s))
> > +	if (ULONG_CMP_LT(sp->srcu_gp_seq_needed_exp, s))
> >   		sp->srcu_gp_seq_needed_exp = s;
> >   	spin_unlock_irqrestore_rcu_node(sp, flags);
> >   }
> > --
> > 1.9.1

--
Thanks,
Byungchul