PPP stalls under moderate CPU load
I'm having a problem where my ppp connection stalls (meaning I don't have any packets coming or going) whenever my CPU load becomes moderately high.
For example, if I'm running rsync I see packets coming and going in kppp like crazy, but if I run a game, tops reports my CPU load at 30% and the packets suddenly die. Quitting the game causes the packets to come back almost instantly (unless I waited to long...)
I use a serial hardware modem (US Robotics 56K Ext Fax modem). I have crtcts enabled in ppp/options, and I tried the other flow control (crtdts) w/o any improvement. I also tried shutting off all compression (nobsdcomp, nodeflate, novj, etc..) thinking that would lessen dependence on the CPU. It didn't help.
FYI I have AMD 64 3400+, slamd64-10.1 distro, kernel 18.104.22.168, pppd version 2.4.2.