Re: Packet gets stuck in NOLOCK pfifo_fast qdisc

[Cong Wang]

On Sat, Apr 3, 2021 at 5:23 AM Jiri Kosina <jikos@xxxxxxxxxx> wrote:
>
> I am still planning to have Yunsheng Lin's (CCing) fix [1] tested in the
> coming days. If it works, then we can consider proceeding with it,
> otherwise I am all for reverting the whole NOLOCK stuff.
>
> [1] https://lore.kernel.org/linux-can/1616641991-14847-1-git-send-email-linyunsheng@xxxxxxxxxx/T/#u

I personally prefer to just revert that bit, as it brings more troubles
than gains. Even with Yunsheng's patch, there are still some issues.
Essentially, I think the core qdisc scheduling code is not ready for
lockless, just look at those NOLOCK checks in sch_generic.c. :-/

Thanks.