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From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-kbuild <linux-kbuild@vger.kernel.org>,
	Michal Marek <mmarek@suse.cz>,
	"H. Peter Anvin" <hpa@linux.intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@elte.hu>,
	Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: RFC: How to handle function tracing, frame pointers and -mfentry?
Date: Sat, 28 Apr 2012 09:34:57 -0700	[thread overview]
Message-ID: <4F9C1C31.7060507@zytor.com> (raw)
In-Reply-To: <20120428083603.GJ27374@one.firstfloor.org>

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.


      parent reply	other threads:[~2012-04-28 16:35 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-27 18:46 RFC: How to handle function tracing, frame pointers and -mfentry? Steven Rostedt
2012-04-27 19:43 ` Steven Rostedt
2012-04-27 20:27 ` Sam Ravnborg
2012-04-27 20:31   ` H. Peter Anvin
2012-04-27 20:57     ` Steven Rostedt
2012-04-27 21:11       ` H. Peter Anvin
2012-04-27 21:27         ` Steven Rostedt
2012-04-28  8:36 ` Andi Kleen
2012-04-28  8:50   ` Sam Ravnborg
2012-04-28  9:11     ` Sam Ravnborg
2012-04-28 12:16       ` Andi Kleen
2012-04-28 16:34   ` H. Peter Anvin [this message]

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