On 3/31/21 1:08 AM, Eric Dumazet wrote: > On Tue, Mar 30, 2021 at 6:02 PM Taehee Yoo <ap420...@gmail.com> wrote: >> >> On 3/31/21 12:40 AM, Eric Dumazet wrote: >> > This seems a serious regression compared to old code (in net tree) >> > >> > Have you added RTNL requirement in all this code ? >> > >> > We would like to use RTNL only if strictly needed. >> >> Yes, I agree with you. >> This patchset actually relies on existed RTNL, which is >> setsockopt_needs_rtnl(). >> And remained RTNL was replaced by mc_lock. >> So, this patchset actually doesn't add new RTNL except in this case. >> >> Fortunately, I think It can be replaced by RCU because, >> 1. ip6_mc_msfget() doesn't need the sleepable functions. >> 2. It is not the write critical section. >> So, RCU can be used instead of RTNL for ip6_mc_msfget(). >> How do you think about it? > > Yes please, do not add RTNL here if we can avoid it. > Okay, I will send a new patch.
> Otherwise some applications will slow down the whole stack, even with > different containers/netns. > > (There is a single RTNL for the whole machine) > Thanks a lot for the review!
