Re: [PATCH] srcu: fix misprint in srcu_funnel_exp_start

From: Ildar Ismagilov
Date: Tue Jan 30 2018 - 14:17:38 EST


I didn't check the performance, because this misprint has been found
accidentally, during studying of a RCU/SRCU code.

2018-01-30 8:37 GMT+03:00 Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>:
> On Mon, Jan 29, 2018 at 09:23:09PM +0300, Ildar Ismagilov wrote:
>> Signed-off-by: Ildar Ismagilov <devix84@xxxxxxxxx>
>
> The original does look backwards, now that you mention it, thank you
> for sending it.
>
> Did you see any performance differences from this patch?
>
> 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 6d5880089ff6..1798d1aa60fa 100644
>> --- a/kernel/rcu/srcutree.c
>> +++ b/kernel/rcu/srcutree.c
>> @@ -599,7 +599,7 @@ static void srcu_funnel_exp_start(struct srcu_struct *sp, struct srcu_node *snp,
>> raw_spin_unlock_irqrestore_rcu_node(snp, flags);
>> }
>> raw_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;
>> raw_spin_unlock_irqrestore_rcu_node(sp, flags);
>> }
>> --
>> 2.11.0
>>
>



--
Best regards
Ildar