Re: [PATCH v8 2/6] rcu/segcblist: Add counters to segcblist datastructure

[Frederic Weisbecker]

On Wed, Oct 21, 2020 at 03:08:09PM -0400, Joel Fernandes (Google) wrote:
>  bool rcu_segcblist_accelerate(struct rcu_segcblist *rsclp, unsigned long seq)
>  {
> -	int i;
> +	int i, j;
>  
>  	WARN_ON_ONCE(!rcu_segcblist_is_enabled(rsclp));
>  	if (rcu_segcblist_restempty(rsclp, RCU_DONE_TAIL))
> @@ -487,6 +508,10 @@ bool rcu_segcblist_accelerate(struct rcu_segcblist *rsclp, unsigned long seq)
>  	if (rcu_segcblist_restempty(rsclp, i) || ++i >= RCU_NEXT_TAIL)
>  		return false;
>  
> +	/* Accounting: everything below i is about to get merged into i. */
> +	for (j = i + 1; j <= RCU_NEXT_TAIL; j++)
> +		rcu_segcblist_move_seglen(rsclp, j, i);
> +

Can you perhaps reuse the below loop to move the seglen?

Thanks.

>  	/*
>  	 * Merge all later callbacks, including newly arrived callbacks,
>  	 * into the segment located by the for-loop above.  Assign "seq"