Performance issues with long lines in shell mode

[David Karr]

I'm using Cygwin Emacs v26.3.

I use shell buffers in Emacs very often. Some of the command lines I run
end up producing output with a large number of lines, and sometimes with
very long lines. If the output is a large number of lines, it doesn't
present any particular problem.  However, if it ends up producing very long
lines (equivalent of a hundred lines or more), I find that it gets very
slow. I generally don't even keep my cursor at the end of the output, so
it's adding output that I'm not even seeing. However, I can still tell that
it's running slowly. If I occasionally jump to the end of the output, I see
it sending characters in bursts, but much less than a line at a time.

If I know that what I'm about to run will create long lines, I generally
try to remember to pipe it directly to a file and then open that file. That
goes much faster than letting it output to the shell.

Is there some mitigation I can configure that will help with this?