Re: [PATCH] x86, cpu: Fix X86_FEATURE_NOPL

From: H. Peter Anvin
Date: Mon Oct 04 2010 - 17:51:56 EST


>>
>> Agreed that this should be cleaned up. However, in the meantime I'd
>> like to keep Borislav's patch in the tree since it makes the code
>> technically correct at least.
>
> I think the cleanup should be easy: on 64-bit unconditionally return
> p6_nops in find_nop_table() since every 64-bit processor should support
> them and on 32-bit never return p6_nops since X86_FEATURE_NOPL is not
> set there and fall back to intel_nops on non-AMD. Which means we can get
> rid of X86_FEATURE_NOPL altogether. Too radical?
>

This is fine with me, but you may want to check with your employer if
the Intel NOPs will perform slower than the 66 ... 90 NOPs on AMD
processors.

-hpa
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