Re: [PATCH:resend] rt: Remove CONFIG_STACK_TRACER from DEBUG_COUNT,and fix reminder block

[Thomas Gleixner]

On Tue, 27 Apr 2010, John Kacur wrote:

> This fix does two things.

This changelog does suck in more than two ways.
 
> 1. It reverts commit 3e39399ef4a742d994570488994be93ef17d4ef5.
> - The above commit added back a warning about CONFIG_STACK_TRACER
> NOT because the warning was necessary but to fix-up a problem where you could
> get an empty REMINDER block in the demg.

The CONFIG_STACK_TRACER printk has been there before and got dropped
for whatever reason, but the DEBUG_COUNT accounting of
CONFIG_STACK_TRACER still remained.

So the conclusion that the printk needs to be added back is _NOT_
completely unreasonable.

> However, CONFIG_STACK_TRACER really should not be in the reminder block.
> Even when configured-in it is not enabled, and thus has neglible impact.

That argument is bogus as it applies to most of the tracing related
config options. 
 
> 2. It removes CONFIG_STACK_TRACER from DEBUG_COUNT which is the proper fix
> for the empty REMINDER block problem.

It's the proper fix if the warning is not justified, which is not
clear at all. At least not from your changelog.

I do not mind the patch per se, but 

1) the changelog should simply say:

   rt: Remove CONFIG_STACK_TRACER from REMINDER block

   Reason: It does not matter because ....

2) the patch should cover _all_ tracing options which have no
   considerable latency impact when just compiled in and not default
   enabled.

Thanks,

	tglx
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