Re: [RFC: 2.6 patch] build kernel/profile.o only when requested

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 20 May 2008 00:53:06 +0300 Adrian Bunk <bunk@kernel.org> wrote:

> Build kernel/profile.o only if CONFIG_PROFILING is enabled.
> 
> This makes CONFIG_PROFILING=n kernels smaller.
> 
> As a bonus, some profile_tick() calls and one branch from schedule() are 
> now eliminated with CONFIG_PROFILING=n (but I doubt these are
> measurable effects).
> 
> This patch changes the effects of CONFIG_PROFILING=n, but I don't think 
> having more than two choices would be the better choice.
> 
> This patch also adds the name of the first parameter to the prototypes 
> of profile_{hits,tick}() since I anyway had to add them for the dummy 
> functions.
> 

Little nits:

> index 05c1cc7..4081fa3 100644
> --- a/include/linux/profile.h
> +++ b/include/linux/profile.h
> @@ -8,8 +8,6 @@
>  
>  #include <asm/errno.h>
>  
> -extern int prof_on __read_mostly;
> -
>  #define CPU_PROFILING	1
>  #define SCHED_PROFILING	2
>  #define SLEEP_PROFILING	3
> @@ -19,14 +17,29 @@ struct proc_dir_entry;
>  struct pt_regs;
>  struct notifier_block;
>  
> +#if defined(CONFIG_PROFILING) && defined(CONFIG_PROC_FS)
> +void create_prof_cpu_mask(struct proc_dir_entry *);

This omits the argument's name, whereas elsewhere you have taken care
to introduce the name where it was missing.

> +#else
> +#define create_prof_cpu_mask(x)			do { (void)(x); } while (0)

I think this could be a static inline, which is neater.

I wonder why create_prof_cpu_mask() is called only by s390.  I suppose
I should I should get the historical-git tree onto this machine and
find out.