At Sun, 27 Jun 2010 23:07:16 -0400, Neil Van Dyke wrote: > What effect does the JIT currently have on debugging backtraces? Or, > how can one get some or all of the benefit of the JIT, but still > reliably get useful backtraces?
The JIT backtraces have gotten slightly better in some corner cases, but not much overall on x86 or PPC. On x86_64, backtraces were originally limited or absent, but that was fixed a while ago. > I see that DrScheme now has an option for disabling some JIT > optimizations. Should I just do whatever that checkbox is doing? I hadn't noticed before, but the checkbox needs to be relabeled by dropping "JIT". It disables bytecode-compiler optimizations, which apply whether or not you are using the JIT. So, if you're getting useful info already without the JIT, then that checkbox isn't the right direction. > Details on my particular system... A while ago, I had to disable the JIT > for a large system so that we could reliably get useful backtraces at > the time (i.e., not just our top-level entry point). The difference between JIT and non-JIT backtraces usually isn't so big. Assuming that it's still a problem (i.e., it wasn't on x86_64 and long enough ago), then probably we need to fix something in the JIT backtrace implementation. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
