On Mon, Jun 13, 2016 at 8:21 PM, Eric Dumazet <eduma...@google.com> wrote: > qdiscs/classes are changed under RTNL protection and often > while blocking BH and root qdisc spinlock. > > When lots of skbs need to be dropped, we free > them under these locks causing TX/RX freezes, > and more generally latency spikes. > > I saw spikes of 50+ ms on quite fast hardware... > > This patch series adds a simple queue protected by RTNL > where skbs can be placed until RTNL is released. > > Note that this might also serve in the future for optional > reinjection of packets when a qdisc is replaced.
No objection from me. It looks like a good optimization before we can improve the qdisc root spinlock. Just one nit: You probably want to keep rtnl_kfree_skbs() within qdisc layer unless you have any plan to use it in other places. Thanks!