On Wed, 2016-06-08 at 23:01 +0200, Florian Westphal wrote:
>
> Would you mind an annotation rather than covering the hole?
>
> --- a/include/net/sch_generic.h
> +++ b/include/net/sch_generic.h
> @@ -71,11 +71,11 @@ struct Qdisc {
> struct gnet_stats_basic_cpu __percpu *cpu_bstats;
> struct gnet_stats_queue __percpu *cpu_qstats;
>
> - struct Qdisc *next_sched;
> - struct sk_buff *gso_skb;
> /*
> * For performance sake on SMP, we put highly modified fields at the
> end
> */
> + struct Qdisc *next_sched ____cacheline_aligned_in_smp;
> + struct sk_buff *gso_skb;
>
>
> ... it creates 16 byte hole after cpu_qstats and keeps the rest as-is
> (i.e. next_sched is at beginning of 2nd cacheline, as before the removal).
>
> I could also cover the hole by moving rcu_head there but it seems fragile
> and doesn't reduce total struct size anyway (we get larger hole at end).
>
> If you have no objection I'd resubmit the series as-is but with this patch.
>
> Let me know, thanks Eric!
This all looks fine to me.
