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

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