Re: [linux-usb-devel] Re: [BK PATCH] USB changes for 2.5.34

David Woodhouse
2002-09-16T14:09:59Z

axboe@suse.de said:
> See, even though I'm not fundamentally against using kernel
> debuggers, I think this is very wrong. Where are you now? You are just
> learning about the bio interface and the changes needed to make it
> run. And this is definitely the most wrong point to start using a
> debugger, and can only result in a dac960 that works by trial and
> error.

Nevertheless, the existence of a case where it's not sensible to use a
debugger does not prove the non-existence of cases where it _is_ sensible
to use a debugger.

A case that happened to me recently -- tail-call optimisations screwed up
the return value of a function somewhere deep in the routing code. Adding a
printk made the problem go away. Staring at the C code was also of no use --
the C code was just fine.

Now, are you seriously suggesting that instead of using GDB to work out WTF
was going on I should have spent three weeks starting at the output of
'objdump -d vmlinux' ?

While my balls are big enough and hairy enough that I don't need to use GDB
to debug my own code, I feel no shame in admitting that I'm so much of a
pussy I can't deal with the above case without GDB.

--
dwmw2