tmux flow control

Question

I'm ssh'ing into a machine running Ubuntu 12.04, and using tmux 1.6, on an ADSL link (8Mbps/1Mbps down/up).

When there's lots of fast terminal output, the link gets saturated and completely unresponsive, and I can't switch tmux windows or anything, and have to kill ssh.

Is there some tmux setting to prevent this? I've seen some patches but it's not clear what they do.

Answer 1

tmux 1.7 and later include a kind of rate limiting. It might help if the output you are dealing with is normal “scrolly” output (lots of normal lines, not (e.g.) a huge base64 encoded block).

Two options control this rate limiting: c0-change-trigger, and c0-change-interval. Basically, if tmux sees more than c0-change-trigger of certain C0 control characters (e.g. backspace, linefeed, carriage return) in 1 millisecond, then it will deferring further updates to the pane for c0-change-interval milliseconds. The defaults are 250 such C0 characters in 1 millisecond will stop pane drawing for 100 milliseconds.