There's definitely something fishy going on... cat'ing a 336MB text file with 6.7M lines in a tmux pane results in 700MB of resident memory usage with 3.3a and ~3.2GB with 3.4, an increase of 4.4x. And since entering copy mode actually *copies* the entire history of the pane into a new memory grid, it allocates the same huge amount of memory and copies everything over. In 3.4 this involves way more memory.
It's also much much slower than 3.3a at actually accepting the output from cat, which is unsurprising. I'll dig deeper. -- Romain Francoise <rfranco...@debian.org> https://people.debian.org/~rfrancoise/
