Message-ID: <50339A85.3080206@redhat.com>
Date: Tue, 21 Aug 2012 17:26:13 +0300
From: Avi Kivity <avi@redhat.com>
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To: Ingo Molnar <mingo@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>, linux-kernel@vger.kernel.org,
        x86@kernel.org, mmarek@suse.cz, linux-kbuild@vger.kernel.org,
        JBeulich@suse.com, akpm@linux-foundation.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: RFC: Link Time Optimization support for the kernel
References: <1345345030-22211-1-git-send-email-andi@firstfloor.org> <20120820074835.GA6710@gmail.com> <20120820101044.GE16230@one.firstfloor.org> <20120821074921.GA10809@gmail.com>
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On 08/21/2012 10:49 AM, Ingo Molnar wrote:
> 
> Can the current implementation of LTO optimize to the level of 
> inlining? A lot of our include file hell situation results from 
> the desire to declare structures publicly so that inlined 
> functions can use them directly.
> 
> If data structures could be encapsulated/internalized to 
> subsystems and only global functions are exposed to other 
> subsystems [which are then LTO optimized] then our include
> file dependencies could become a *lot* simpler.

I think modules break this (if I understand what you mean correctly).
If the main kernel exposes symbol x as a global function, then lto will
not inline it into a module.

-- 
error compiling committee.c: too many arguments to function
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