On Fri, 25 Apr 2008, Kris Kennaway wrote:
Unfortunately we need the rest of the stack. Can you either try to reproduce with DDB in the kernel and obtain a stack trace from there, or if this is not possible then try recompiling the kernel with -O instead of -O2 which tends to produce better stack traces.
I wonder why there haven't been more reports of gcc-4.2 -O[2] breaking things (I probably read the wrong lists). -O2 almost completely breaks kernel profiling and debugging using ddb, mainly by inlining functions that are only used once. Even -O is documented as enabling -funit-at-a-time, which is documented as enabling -finline-functions-called-once. -funit-at-a-time gives the possibility of inlining functions that are instantiated before they are used, and then -finline-functions-called-once tends to inline them. However, this doesn't seem to happen very often with only -O. Maybe -O only inlines small functions, but -O2 inlines all functions that are only called once. Losing the symbols and frames for large inlined functions is especially annoying. I started using -O2 for kernels about a year ago because although it it has little effect (usually negative) in normal use, it gave an optimization of a whole 1 to 5% in network microbenchmarks that I was working on. Bruce _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
