From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <andi@firstfloor.org>
Subject: Re: [patch] measurements, numbers about CONFIG_OPTIMIZE_INLINING=y impact
Date: Fri, 9 Jan 2009 19:02:13 +0100
Message-ID: <20090109180213.GH26290@one.firstfloor.org>
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Cc: Andi Kleen <andi@firstfloor.org>, Matthew Wilcox <matthew@wil.cx>,
	"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
	jim owens <jowens@hp.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Chris Mason <chris.mason@oracle.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	paulmck@linux.vnet.ibm.com, Gregory Haskins <ghaskins@novell.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-btrfs <linux-btrfs@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Nick Piggin <npiggin@suse.de>,
	Peter Morreale <pmorreale@novell.com>,
	Sven Dietrich <SDietrich@novell.com>, jh@suse.cz
To: Dirk Hohndel <hohndel@infradead.org>
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> I think that's the point. gcc will not get it right. 

I don't think that's necessary an universal truth. It 
can be probably fixed.

> So we need to do it ourselves in the kernel sources.
> We may not like it, but it's the only way to guarantee reproducable
> reliable inline / noinline decisions.

For most things we don't really need it to be reproducable,
the main exception are the inlines in headers.

Universal noinline would also be a bad idea because of its
costs (4.1% text size increase). Perhaps should make it
a CONFIG option for debugging though.

-Andi



> 
> /D
> 
> -- 
> Dirk Hohndel
> Intel Open Source Technology Center
> 

-- 
ak@linux.intel.com