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Date: Thu, 05 Apr 2007 14:08:24 -0700
From: Jeremy Fitzhardinge <jeremy@goop.org>
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To: Andi Kleen <ak@suse.de>
CC: Benjamin LaHaise <bcrl@kvack.org>, Ingo Molnar <mingo@elte.hu>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: What protects cpu_tlbstate?
References: <4615518A.4070003@goop.org> <200704052228.36590.ak@suse.de> <46156366.70206@goop.org> <200704052303.35846.ak@suse.de>
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Andi Kleen wrote:
>> Hm, I was more wondering about simple compiler reordering.  Does the
>> relative order of setting and reading cpu_tlbstate.state, active_mm and
>> the mm->cpu_vm_mask matter?
>>     
>
> Hmm, perhaps a barrier between state and active_mm might be a good idea.
> Setting active_mm after state might be problematic.
> cpu_vm_mask should be already a memory barrier.
>   

Should leave_mm update active_mm and set the state to TLBSTATE_OK?  Just
reloading cr3 seems a bit blunt.

    J