Re: [uClinux-dev] Kernel 2.6 size increase - get_current()?

From: Hollis Blanchard (hollisb@us.ibm.com)
Date: Thu Jul 24 2003 - 14:51:16 EST


On Thursday, Jul 24, 2003, at 14:37 US/Central, Alan Cox wrote:

> On Iau, 2003-07-24 at 16:30, Hollis Blanchard wrote:
>> So you're arguing for more inlining, because icache speculative
>> prefetch will pick up the inlined code?
>
> I'm arguing for short inlined fast paths and non inlined unusual
> paths.
>
>> Or you're arguing for less, because code like get_current() which is
>> called frequently could have a single copy living in icache?
>
> Depends how much the jump costs you.

And also how big your icache is, and maybe even cpu/bus ratio, etc...
which depend on the arch of course.

So as I saw Ihar suggest earlier in this thread, perhaps there should
be two inline directives: must_inline (for code whose correctness
depends on it) and could_help_performance_inline. Then different archs
could #define could_help_performance_inline as appropriate.

-- 
Hollis Blanchard
IBM Linux Technology Center

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