Anyone here willing jump through a few hoops to get us profiling data for your specific setups? If we get right clues we might be able to issue a patch:
git clone https://github.com/zerotier/ZeroTierOne.git
cd ZeroTierOne
make one -j$(nproc) ZT_DEBUG=1
If compilation doesn’t work you may need some or all of the following:
sudo apt install git make lldb libssl-dev
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
Then once compilation succeeds:
NOTE: Stop your system ZeroTier instance before continuing to the next step. This new debug instance will use the same identities and port and will be functionally identical.
sudo lldb ./zerotier-one
lldb> run
Wait for high CPU utilization and then:
^C
lldb> bt
And then send us the output.
Optionally sending a bt for each thread:
^C
lldb> thread list
lldb> t 1
lldb> bt
lldb> t 2
lldb> bt
...
If you did this a few times it could help us pin down where ZT is spending most of its time. Alternatively using gprof is an option but it’s a little harder to use.