$ time node -e 'new require("markdown-it")("commonmark").parse("*_".repeat(10000))'
0.65user 0.01system 0:00.65elapsed 103%CPU (0avgtext+0avgdata 43360maxresident)k
0inputs+0outputs (0major+5493minor)pagefaults 0swaps
$ time node -e 'new require("markdown-it")("commonmark").parse("*_".repeat(20000))'
3.05user 0.01system 0:03.06elapsed 100%CPU (0avgtext+0avgdata 49972maxresident)k
0inputs+0outputs (0major+7101minor)pagefaults 0swaps
$ time node -e 'new require("markdown-it")("commonmark").parse("*_".repeat(40000))'
19.67user 0.05system 0:20.29elapsed 97%CPU (0avgtext+0avgdata 65260maxresident)k
0inputs+0outputs (0major+10989minor)pagefaults 0swaps
$ time node -e 'new require("markdown-it")("commonmark").parse("*_".repeat(80000))'
88.29user 0.17system 1:30.10elapsed 98%CPU (0avgtext+0avgdata 102900maxresident)k
0inputs+0outputs (0major+20453minor)pagefaults 0swaps