Core Scheduling for SMT

configname: CONFIG_SCHED_CORE

Linux Kernel Configuration
└─>Core Scheduling for SMT
In linux kernel since version 5.2 (release Date: 2019-07-07)  
This option permits Core Scheduling, a means of coordinated task
selection across SMT siblings. When enabled -- see
prctl(PR_SCHED_CORE) -- task selection ensures that all SMT siblings
will execute a task from the same 'core group', forcing idle when no
matching task is found.

Use of this feature includes:
- mitigation of some (not all) SMT side channels;
- limiting SMT interference to improve determinism and/or performance.

SCHED_CORE is default disabled. When it is enabled and unused,
which is the likely usage by Linux distributions, there should
be no measurable impact on performance.