Bug#265951: more info

[Lee Revell]

OK, I have confirmed that this also affects rxvt, but to a lesser
extent.  It seems that the 'heavier' the terminal program, the more the
behavior is exacerbated.

Here is a good test to reproduce the problem:

 for f in 1 2 3 4 5 6 7 8 9 10; do (time cat f) 2>> file; done

So this bug report needs to be moved to another package, but I have mo
idea which.

rxvt results:

real    0m0.006s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.001s
sys     0m0.005s

real    0m0.005s
user    0m0.002s
sys     0m0.003s

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.002s
sys     0m0.003s

real    0m0.155s <--- slow one
user    0m0.000s
sys     0m0.006s

real    0m0.115s <--- slow one
user    0m0.001s
sys     0m0.003s

real    0m0.011s
user    0m0.002s
sys     0m0.002s

real    0m0.005s
user    0m0.000s
sys     0m0.005s

real    0m0.005s
user    0m0.003s
sys     0m0.002s

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.002s

xterm results:

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.001s
sys     0m0.004s

real    0m0.005s <--- fast
user    0m0.003s
sys     0m0.002s

real    0m2.518s <--- boundary
user    0m0.000s
sys     0m0.006s

real    0m3.349s <--- slow one
user    0m0.001s
sys     0m0.006s

real    0m3.162s <--- slow one
user    0m0.002s
sys     0m0.005s

real    0m3.260s <--- slow one
user    0m0.001s
sys     0m0.005s

real    0m0.006s <--- fast again
user    0m0.001s
sys     0m0.004s

real    0m0.005s
user    0m0.002s
sys     0m0.003s

So while rxvt shows a slowdown of ~60x, for xterm the slowdown is
~600x.  Using the script above to test also reveals that whatever
condition causes the slowdown can happen in the middle of a programs
output.

Lee