Okay, I ran a little experiment - here's the size of the debug sections that Fission would keep (for base library): .debug_abbrev: 8932 - 0.06% .debug_line: 374134 - 2.6% .debug_frame: 671200 - 4.5% Not that much. On the other hand, .debug_info is a significant contributor: .debug_info(full): 4527391 - 30% Here's what this contains: All procs get a corresponding DWARF entry, and we declare all Cmm blocks as "lexical blocks". The latter isn't actually required right now - to my knowledge, GDB simply ignores it, while LLDB shows it as "inlined" routines. In either case, it just shows yet more GHC-generated names, so it's really only useful for profiling tools that know Cmm block names. So here's what we get if we strip out block information: .debug_info(!block): 1688410 - 11% This eliminates a good chunk of information, and might therefore be a good idea for "-g1" at minimum. If we want this as default for 7.10, this would make the total overhead about 18%. Acceptable? I can supply a patch if needed. Just for comparison - for Fission we'd strip proc records as well, which would cause even more extreme savings: .debug_info(!proc): 36081 - 0.2% At this point the overhead would be just about 7% - but without doing Fission properly this would most certainly affect debuggers. Greetings, Peter On 03/01/2015 21:22, Johan Tibell wrote:
How much debug info (as a percentage) do we currently generate? Could we just keep it in there in the release?