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

From: Dave Jones
Date: Thu Nov 12 2009 - 14:09:34 EST


On Thu, Nov 12, 2009 at 06:59:08PM +0100, Ingo Molnar wrote:
> > It's an ABI. Keep it stable, please.
>
> That's generally true, but i'm not suggesting that: i'm suggesting to
> _clear_ the HT flag from the cpufeatures if there's only one sibling.
> It's meaningless in that case and as the link quoted by the original
> patch shows many people are confused by that.
>
> I have such a box so i can test it. (but i dont expect any problems)

I agree that it's an ABI change, but any software depending on its current
state has to implement a fallback for the case where 'ht' isn't present anyway
unless there's some program that only runs on ht capable hardware, which
sounds just crazy.

The only potential for breakage that I can see is that code that is tuned
to be run in the HT case will stop running in cases where it shouldn't.
Which sounds like a positive thing to me.

Dave

--
http://www.codemonkey.org.uk
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/