RE: [PATCH 1/1] Bumps limit of maximum core ID from 32 to 128.

Odzioba, Lukasz
2015-10-13T22:45:21Z

On Wednesday, October 14, 2015 at 12:26 AM, Guenter Roeck wrote:
> Pardon my ignorance ... those are Xeon Phi processors, and support up to
> 244 threads (for Knights Corner). Programming datasheet isn't easily available,
> so I have to guess a bit. Following the processor numbering scheme of "ordinary"
> processors, the CPU ID can therefore be up to 244 (at least) already today,
> meaning the limit would have to be 256 (assuming that the processor does support
> per-core temperature sensors). On the other side, the public datasheet suggests
> that there are only three temperature sensors.

> What am I missing here ?

Knights Corner can have up to 61 cores with 4 threads per core, so up to 244 threads.
All HT siblings reads temperature from the same core and coretemp driver is aware of it.
That's it needs just one temp_data structure for all threads on given core.
I tested 128 on real HW myself.

Thanks,
Lukas