sched: Add CONFIG_SCHED_CORE help text

Hugh noted that the SCHED_CORE Kconfig option could do with a help
text.

Requested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Link: https://lkml.kernel.org/r/YKyhtwhEgvtUDOyl@hirez.programming.kicks-ass.net
This commit is contained in:
Peter Zijlstra 2021-05-25 08:53:28 +02:00
parent a8ea6fc9b0
commit 7b419f47fa

View File

@ -104,4 +104,18 @@ config SCHED_CORE
bool "Core Scheduling for SMT"
default y
depends on SCHED_SMT
help
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 enabled when SCHED_SMT is enabled -- when
unused there should be no impact on performance.