sched: Core-wide rq->lock
Introduce the basic infrastructure to have a core wide rq->lock.
This relies on the rq->__lock order being in increasing CPU number
(inside a core). It is also constrained to SMT8 per lockdep (and
SMT256 per preempt_count).
Luckily SMT8 is the max supported SMT count for Linux (Mips, Sparc and
Power are known to have this).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Don Hiatt <dhiatt@digitalocean.com>
Tested-by: Hongyu Ning <hongyu.ning@linux.intel.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/YJUNfzSgptjX7tG6@hirez.programming.kicks-ass.net
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 4160173..ea1e333 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -99,3 +99,9 @@
Interesting if you want the same pre-built kernel should be used for
both Server and Desktop workloads.
+
+config SCHED_CORE
+ bool "Core Scheduling for SMT"
+ default y
+ depends on SCHED_SMT
+