Hi Paul,
Signed-off-by: Lihao Liang <lihao.li...@gmail.com>
Many thanks,
Lihao.
On 2017/11/29 9:14, Paul E. McKenney wrote:
> On Wed, Nov 29, 2017 at 11:51:51AM +1100, Stephen Rothwell wrote:
>> Hi Paul,
>>
>> Commit
>>
>> d7e182c9c324 ("rcu: Remove unnecessary spinlock in
>> rcu_boot_init_percpu_data()")
>>
>> is missing a Signed-off-by from its author.
>
> Good catch, Stephen!
>
> Lihao, would you please get me you Signed-off-by? The patch is below.
>
> Thanx, Paul
>
> ------------------------------------------------------------------------
>
> commit d7e182c9c32480c1f579dd888ac50e88bfb39596
> Author: Liang Lihao <liangli...@huawei.com>
> Date: Wed Nov 22 19:00:55 2017 +0000
>
> rcu: Remove unnecessary spinlock in rcu_boot_init_percpu_data()
>
> Since rcu_boot_init_percpu_data() is only called at boot time,
> there is no data race and spinlock is not needed.
>
> Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
>
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index 69722817d6d6..0abe1db53d70 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -3636,12 +3636,9 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf)
> static void __init
> rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
> {
> - unsigned long flags;
> struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
> - struct rcu_node *rnp = rcu_get_root(rsp);
>
> /* Set up local state, ensuring consistent view of global state. */
> - raw_spin_lock_irqsave_rcu_node(rnp, flags);
> rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu);
> rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
> WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != 1);
> @@ -3649,7 +3646,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state
> *rsp)
> rdp->cpu = cpu;
> rdp->rsp = rsp;
> rcu_boot_init_nocb_percpu_data(rdp);
> - raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
> }
>
> /*
>
>
>
