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

From: Adrian Bunk
Date: Tue May 20 2008 - 06:45:49 EST


On Tue, May 20, 2008 at 03:34:44AM -0700, Andrew Morton wrote:
> On Tue, 20 May 2008 13:21:50 +0300 Adrian Bunk <bunk@xxxxxxxxxx> wrote:
>
> > On Tue, May 20, 2008 at 02:01:21AM -0700, Andrew Morton wrote:
> > > On Tue, 20 May 2008 00:53:06 +0300 Adrian Bunk <bunk@xxxxxxxxxx> 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.
> > >...
> >
> > In these two cases I only moved code.
> >
> > And I actually moved the other code and git just decided to move the
> > code that stayed instead since it creates less changed lines...
>
> umm, you also changed the declarations of profile_tick() and
> profile_hits() but not of create_prof_cpu_mask().
>...

For profile_{hits,tick}() I added dummies.

But I didn't touch create_prof_cpu_mask() at all.

I'm very unsure how many cleanups I should stuff into such patches, and
I'd actually rather expected someone telling I shouldn't have touched
the existing profile_{hits,tick}() prototypes...

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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