Re: RFC: How to handle function tracing, frame pointers and -mfentry?

From: H. Peter Anvin
Date: Sat Apr 28 2012 - 12:36:15 EST


On 04/28/2012 01:36 AM, Andi Kleen wrote:
>
> Kconfig just needs to learn how to run the target compiler
>
> I think that's the right direction. Right now our main
> Makefiles get polluted more and more with "test compiles", each
> of which makes a "null make" slower and slower.
>
> I just measured and a null compile (nothing changes) of a current
> tree calls "gcc" 141 times.
>
> All this stuff should be cached in the Kconfig instead.
>
> It may break some obscure setups (that can be probably fixed without
> too much effort), but the development turnaround improvement
> for everyone else would be worth it.
>

I don't think it is a performance issue as much as a utility issue.
When Kconfig can't actually reflect what is built into the resulting
kernel, that is a problem.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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