On 12/16/2018 2:01 PM, Jiri Kosina wrote:
On Mon, 17 Dec 2018, Barry Kauler wrote:
Thanks for the response. So I guess it comes down to basic philosophy:
"SMT is a distinct feature, separate from SMP, and I think that it is important to keep that distinction."
You guys have chosen to remove that distinction, and to remove the choice for many specialised, such as embedded, situations, where they would maybe want that choice.
They have that choice. SMT can be disabled on kernel cmdline, and in many cases also in BIOS.
SCHED_SMT does not control hyperthreading... it just controls the OS awareness of it in the scheduler (e.g. it knows about shared caches). Even without SCHED_SMT will you see all the logical CPUs... you just get more shitty scheduling behavior.