Re: [Xen-devel] [PATCH] x86: optimize this_cpu()

To:	Jan Beulich <JBeulich@xxxxxxxxxx>
Subject:	Re: [Xen-devel] [PATCH] x86: optimize this_cpu()
From:	Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date:	Tue, 13 Jul 2010 16:03:48 +0100
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On 13/07/2010 15:57, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:

>> Where does that come from?
> 
> From various assembly files, defining GET_CURRENT() or alike
> on their own. grep-ing for STACK_SIZE had helped me noticing
> the issue. Likewise GET_GUEST_REGS() implies that
> "guest_cpu_user_regs" is the first field of struct cpu_info (but
> this I would consider expected).

Hmm, I think I will do a cleanup patch, thanks!

On this theme, just look at how the code in arch/x86/acpi/wakeup_prot.S
(lines 162--167) does multiple hardcoded indirections to get at the current
domain_id. That is absolutely shocking!

 -- Keir

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Re: [Xen-devel] [PATCH] x86: optimize this_cpu()