[PATCH] powerpc/xive: Fix/improve verbose debug output

[Michael Ellerman]

Benjamin Herrenschmidt <benh at kernel.crashing.org> writes:

> On Fri, 2017-04-28 at 13:07 +1000, Michael Ellerman wrote:
>> Benjamin Herrenschmidt <benh at kernel.crashing.org> writes:
>> 
>> > The existing verbose debug code doesn't build when enabled.
>> 
>> So why don't we convert all the DBG_VERBOSE() to pr_devel()? 
>
> pr_devel provides a bunch of debug at init/setup/mask/unmask etc... but
> the system is still usable

OK so those could be converted to pr_debug().

> DBG_VERBOSE starts spewing stuff on every interrupt and eoi, the system
> is no longer usable.

And those could stay at pr_devel(), requiring a #define DEBUG and
recompile to enable.

>> If there's non-verbose debug that we think would be useful to
>> differentiate from verbose then those could be pr_debug() - which means
>> they'll be jump labelled off in most production kernels, but still able
>> to be enabled.
>
> Maybe... I don't like the giant "debug" switch accross the whole
> kernel, though.

Not sure what you mean. You can enable pr_debug()s individually, by
function, by module, by file, or for the whole kernel.

To enable everything in xive you'd do:

# echo 'file *xive* +p' > /sys/kernel/debug/dynamic_debug/control

Or boot with: loglevel=8 dyndbg="file *xive* +p"

cheers