Re: [PATCH] add a counter in grub_dprintf

["Vesa Jääskeläinen" <chaac@nic.fi>]

Pavel Roskin wrote:
> On Sun, 2008-06-29 at 13:22 +0200, Robert Millan wrote:
>> On Thu, Jun 26, 2008 at 05:20:51PM +0200, Javier Martín wrote:
> 
>>> Whoops, sorry, I meant that grub_mkimage would create two core.img
>>> images, one per kernel.img version, and then grub_install would copy
>>> them as usual. Then grub_setup would embed/set up the normal core.img
>>> or the debug version based on a switch. What I propose is basically
>>> modifying grub_mkimage to allow choosing the kernel.img file used and
>>> then adding some lines to grub_install so that the two versions of
>>> core.img are generated (but only the selected is embedded).
>> Ah;  then it sounds fine, I guess.
> 
> Sorry for entering this discussion so late.  I can tell from my
> experience that most debug code is only useful to debug once specific
> problem.  Once the problem is fixed, the debug code is not needed.  If
> another problem is found, then some new debug code should be written to
> debug that problem.
> 
> Generic debug code may be useful to get information from users if only
> they can reproduce the problem.  But even then, if may be better to add
> a few lines to test certain assumptions rather than try to glean useful
> pieces of information from a long generic log.
> 
> Adding a complicated mechanism for having debug and non-debug images
> looks like an overkill to me.  It could create more problems than it
> would fix.

One way to proceed here is to use debugger for the original benchmarking 
purpose.

You would put timed breakpoints, when breakpoint is found, time would be 
recorded and then execution would be automatically continued. This can 
be almost fully external to the code being executed.