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From: David Woodhouse <dwmw2@infradead.org>
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References: <20020916090616.GF12364@suse.de>  <Pine.LNX.4.44.0209151103170.10830-100000@home.transmeta.com> <E17qejV-00008L-00@starship> 
To: Jens Axboe <axboe@suse.de>
Cc: Daniel Phillips <phillips@arcor.de>,
       Linus Torvalds <torvalds@transmeta.com>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>,
       David Brownell <david-b@pacbell.net>,
       Matthew Dharm <mdharm-kernel@one-eyed-alien.net>,
       Greg KH <greg@kroah.com>, linux-usb-devel@lists.sourceforge.net,
       linux-kernel@vger.kernel.org
Subject: Re: [linux-usb-devel] Re: [BK PATCH] USB changes for 2.5.34 
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Date: Mon, 16 Sep 2002 15:14:03 +0100
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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


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