Re: net: suspicious RCU usage in nf_hook

[Eric Dumazet]

On Wed, Feb 1, 2017 at 3:29 PM, Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote:

> Not sure if it is better. The difference is caught up in net_enable_timestamp(),
> which is called setsockopt() path and sk_clone() path, so we could be
> in netstamp_needed state for a long time too until user-space exercises
> these paths.
>
> I am feeling we probably need to get rid of netstamp_needed_deferred,
> and simply defer the whole static_key_slow_dec(), like the attached patch
> (compile only).
>
> What do you think?

I think we need to keep the atomic.

If two cpus call net_disable_timestamp() roughly at the same time, the
work will be scheduled once.