Re: [PATCH RFC] x86: fix confusing name of /proc/cpuinfo "ht" flag

From: H. Peter Anvin
Date: Thu Nov 12 2009 - 02:08:58 EST


On 11/11/2009 10:59 PM, Ingo Molnar wrote:
>
> * Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> wrote:
>
>> "ht" flag indicates only ability to detect siblings not HT presence
>> itself.
>>
>> Inspired by:
>> http://www.codemonkey.org.uk/2009/11/10/common-hyperthreading-misconception/
>
> i think instead of changing 'ht' to 'ht_detect', it would be even more
> intuitive to only expose the 'ht' flag if the ht-detect capability is
> there _and_ if the number of siblings is 2 or more.
>
> That way we dont change it - we just 'hide' the 'ht' string on the
> category of systems that can enumerate HT via the CPUID but dont
> actually have HyperThreading.
>

/proc/cpuinfo is a user-space visible ABI. Changing it is bad chicken.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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