Messages in this thread | | | Date | Fri, 16 Nov 2012 15:06:03 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH v4 6/8] x86/ftrace: Use __pa_symbol instead of __pa on C visible symbols |
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On 11/16/2012 02:45 PM, Steven Rostedt wrote: > > #define __pa(x) __phys_addr((unsigned long)(x)) > #define __pa_symbol(x) __pa(__phys_reloc_hide((unsigned long)(x))) > > I'm confused. __pa_symbol() just calls __pa() with some macro magic to > its parameter. How is this a performance improvement? >
One of the earlier patches in this series changes __pa_symbol() to avoid the conditional hidden inside __phys_addr(), since by definition a symbol can only be on one side of that branch.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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