This release mainly improves replay performance dramatically, as I documented in November. It took a while to stabilize for release, partly because we ran into a kernel bug that caused rr tests (and sometimes real rr usage) to totally lock up machines. This release contains a workaround for that kernel bug. It also contains support for the gdb find command, and fixes for a number of other bugs.

http://robert.ocallahan.org/2016/02/rr-410-released.html