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Re: [Xen-devel] [PATCH] apic: clean up msr handling

To: "Christoph Egger" <Christoph.Egger@xxxxxxx>
Subject: Re: [Xen-devel] [PATCH] apic: clean up msr handling
From: "Jan Beulich" <JBeulich@xxxxxxxxxx>
Date: Fri, 11 Jun 2010 14:40:48 +0100
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>>> On 11.06.10 at 15:22, Christoph Egger <Christoph.Egger@xxxxxxx> wrote:
>-static inline void write_efer(u64 val)
>-{
>-    this_cpu(efer) = val;
>-    wrmsrl(MSR_EFER, val);
>-}
>+#define write_efer(val) do { \
>+    this_cpu(efer) = val; \
>+    wrmsrl(MSR_EFER, val); \
>+} while(0)

This isn't a good change imo: You now require all current and future
users of write_efer() to not pass expressions with side effects.

Also, is doesn't really look like a cleanup to me, more like a
complication.

Jan



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