summaryrefslogtreecommitdiff
path: root/kernel/Kconfig.preempt
diff options
context:
space:
mode:
authorPeter Zijlstra <peterz@infradead.org>2021-05-25 08:53:28 +0200
committerPeter Zijlstra <peterz@infradead.org>2021-06-01 16:00:10 +0200
commit7b419f47facd286c6723daca6ad69ec355473f78 (patch)
treeb179914710d03ba238938387c61cf756b175e2cb /kernel/Kconfig.preempt
parenta8ea6fc9b089156d9230bfeef964dd9be101a4a9 (diff)
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
Diffstat (limited to 'kernel/Kconfig.preempt')
-rw-r--r--kernel/Kconfig.preempt14
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index ea1e3331c0ba..bd7c4147b9a8 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -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.
+