hwpmc ktrdump: failed to resolve ktr symbols

[shreyank amartya]

Hi,

I'm trying to collect traces from hwpmc module. I compiled the module with
-DHWPMC_DEBUG option and set the sysctl kern.hwpmc.debugflags but I'm
unable to retrive the traces using ktrdump. I get this error message:

ktrdump: failed to resolve ktr symbols

I'm guessing that this error occurs because the symbols for hwpmc module
(compiled and loaded separately) are not a part of kernel. If this is the
case, then how do I get those symbols. In the ktr man page its also
mentioned that ddb and gdb can retrieve ktraces.

I found the ddb command show ktr. But how do I invoke ddb (without a panic)?

I'm unable to find how can I use gdb to view the traces (I launched kgdb
but could not find a command to show kernel traces).

Any idea on how to get ktrdump working? Or get the kernel traces.

Thanks
Shreyank