[cfarm-users] Correct number of CPU/cores/threads (Was: Setting up GitLab CI for git.git on the farm)

[Baptiste Jonglez]

On 20-12-18, Segher Boessenkool wrote:
> Hi!
> 
> On Thu, Dec 20, 2018 at 12:49:59PM +0100, Baptiste Jonglez via cfarm-users wrote:
> > So, I just added pretty usage bars [1] to the list of machine :)
> 
> Thanks.  But maybe it should be presented differently?
> 
> The page now is much too wide to fit on a screen, and those little bars
> are all jumbled around, so it is hard to get information from this.  The
> links ("CPU graphs etc.) distract a lot from the information in that
> column, too.

Hmm yes, I'm not an expert in web design, to say the least…  I have
reduced the text size a bit, it should be better now!

> I normally use
>   lscfg -vp | grep proc
> (no idea how good *that* is, but it does the job).
> 
> gcc111 is 12 cores, 48 threads; gcc119 is 16 cores, 128 threads.

Thanks, I have updated the page.  I assume both have 2 sockets?

> > I realize now that "CPU" vs "cores" is a simplistic distinction for some
> > machines.  I tend to take the definition "CPU = physical socket" but that
> > sounds incorrect for the aarch64 machines: do they really have 8 CPU
> > sockets as reported by lscpu?  Or is it just that each core has its own L3
> > cache so it can be considered to be an independent CPU?
> 
> Many people use cpu = core.  Linux uses cpu = thread.  Some people use
> cpu = die; and some (like you) use cpu = package (not everyone has sockets).
> 
> L3 cache topology does not have much to do with cpu topology.

I see, thanks for the explanation.

Baptiste
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