Robert O'Callahan. Christian. Repatriate Kiwi. Hacker. I just made a performance improvement to the (single-threaded) rr sources command to cache the results of access system calls checking for directory existence. It's a simple and very effective optimization on my Skylake, Linux 5.12 laptop: Before: [roc@localhost code]$ time rr sources ~/pernosco/main/test-tmp/basics-demo >& ~/tmp/output2 real
