Subject: Re: [bloat] Measuring header file bloat effects on kernel build performance: a more than 2x slowdown ...

From: Ingo Molnar <[email-masked]>
Date: Mon, 23 May 2011 19:01:26 +0200

* Linus Torvalds <[email-masked]> wrote:

> On Mon, May 23, 2011 at 2:09 AM, Ingo Molnar <[email-masked]> wrote:
> >
> > I've attached a totally hacky patch that removes all the big #include's from
> > kernel/pid.c and includes all structure and API definitions explicitly.
> 
> Hmm.
> 
> A less hacky patch might be to split up "sched.h" into multiple
> smaller things and at least get *part* of the way.
> 

Yeah, absolutely - Peter already raised that a couple of days ago in a sched.h 
discussion so it's on the radar.

The hacky patch was really just a throw-away attempt to see where we stand - we 
only had vague impressions about the level of problems we have, now we know 
some numbers.

> A lot of things want "struct task_struct" (and in some cases thread_info, but 
> that's already split).
> 
> Much fewer care about the signal stuff.
> 
> And many things probably don't even need the task_struct definition, and 
> might be perfectly happy with just function calls rather than having intimate 
> knowledge of the structure layout and an inline function.

Yeah.

Thanks,

	Ingo