Re: CPU numbering & hyperthreading

From: Chuck Ebbert
Date: Tue Jul 18 2006 - 16:52:26 EST


In-Reply-To: <44BC4200.90308@xxxxxxxxxxxxx>

On Mon, 17 Jul 2006 22:05:52 -0400, Andrew Athan wrote:
>
> I have two highly CPU/memory/network intensive processes with 3-5
> threads each. I am using sched_setaffinity calls to make sure these two
> processes never compete for the same physical CPU. Am I right to assume
> that CPU #0 and #1 vs CPU #2 and #3 are separate physical CPUs on a
> 2-CPU w/ hyperthreading box?
>
> I've spent some time looking, but I did not find documentation on
> exactly how CPUs are numbered in a hyperthreaded box.

There's no fixed numbering.

If you want to know the die/core/thread layout, check out
Documentation/cputopology.txt.

--
Chuck
And did we tell you the name of the game, boy, we call it Riding the Gravy Train.
-
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/