Re: [PATCH net,v2] net: sched: tbf: don't call qdisc_put() while holding tree lock

[shaozhengchao]

On 2022/9/6 2:13, Cong Wang wrote:
> On Fri, Aug 26, 2022 at 09:39:30AM +0800, Zhengchao Shao wrote:
> > The issue is the same to commit c2999f7fb05b ("net: sched: multiq: don't
> > call qdisc_put() while holding tree lock"). Qdiscs call qdisc_put() while
> > holding sch tree spinlock, which results sleeping-while-atomic BUG.
>
> Hm, did you see an actual warning here??
>
> The commit you mentioned above is a classful Qdisc which accepts
> user-specified child Qdisc, but TBF technically does not, I don't think
> you can change its default fifo.
>
> Thanks.

Hi Wang:
	Thank you for your reply. My apologise. I don't see the
warning here. Yes, TBF is classless qdisc, its default fifo is
bfifo and reset or destroy process will not sleep. So, it's not
a issue. Should I revert it, or keep it in this format(qdisc_put
out of holding sch tree spinlock).


Zhengchao Shao