Subject: Re: [PATCH net-next v2 1/2] net: sched: add empty status flag for NOLOCK qdisc

From: Eric Dumazet <[email-masked]>
Date: Fri, 22 Mar 2019 06:56:27 -0700

On 03/22/2019 01:30 AM, Paolo Abeni wrote:
> The queue is marked not empty after acquiring the seqlock,
> and it's up to the NOLOCK qdisc clearing such flag on dequeue.
> Since the empty status lays on the same cache-line of the
> seqlock, it's always hot on cache during the updates.
> 

>  
> +static inline bool qdisc_is_empty(struct Qdisc *qdisc)

const struct Qdisc *qdisc

> +{
> +	if (qdisc->flags & TCQ_F_NOLOCK)
> +		return qdisc->empty;
> +	return !qdisc->q.qlen;
> +}
> +

Other than that :

Reivewed-by: Eric Dumazet <[email-masked]>