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Date: Sat, 14 Mar 2015 12:16:48 +0100
From: Borislav Petkov <bp@suse.de>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>, Ingo Molnar <mingo@kernel.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Pekka Riikonen <priikone@iki.fi>, Rik van Riel <riel@redhat.com>,
        Suresh Siddha <sbsiddha@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        "Yu, Fenghua" <fenghua.yu@intel.com>,
        Quentin Casasnovas <quentin.casasnovas@oracle.com>
Subject: Re: [PATCH 0/1] x86/cpu: don't allocate fpu->state for swapper/0
Message-ID: <20150314111648.GD3114@pd.tnic>
References: <54F74F59.5070107@intel.com>
 <20150313182656.GA8249@redhat.com>
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On Fri, Mar 13, 2015 at 07:26:56PM +0100, Oleg Nesterov wrote:
> Hello.
> 
> This patch is "out of order" a bit, but since Borislav mentioned this
> during review...
> 
> And I was going to send the 2nd one (below), but it turns out that
> __init_refok is not discarded? So is there any way to do
> 
> 	void __init init_function();
> 
> 	void non_init_func()
> 	{
> 		if (can_only_be_true_before_free_initmem)
> 			init_function();
> 	}
> 
> and avoid the warning?

Actually, I was wondering if we could be even more radical and do
the boot cpu-specific stuff only in the BSP boot path. For example,
somewhere down that path:

start_kernel
|-> check_bugs
   |-> check_fpu		--- btw, we do FPU stuff here already too
   |-> xstate_enable_boot_cpu

instead of this state machine with function pointers hackery.

I'll try to play with this and see whether something breaks.

Thanks.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--