[PATCH 2/5] sched: introduce per-cpu var next_cpu to track search limit
From: subhra mazumdar
Date: Thu Jun 28 2018 - 18:44:50 EST
Introduce a per-cpu variable to track the limit upto which idle cpu search
was done in select_idle_cpu(). This will help to start the search next time
from there. This is necessary for rotating the search window over entire
LLC domain.
Signed-off-by: subhra mazumdar <subhra.mazumdar@xxxxxxxxxx>
---
kernel/sched/core.c | 2 ++
kernel/sched/sched.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8d59b25..b3e4ec1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -20,6 +20,7 @@
#include <trace/events/sched.h>
DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
+DEFINE_PER_CPU_SHARED_ALIGNED(int, next_cpu);
#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
/*
@@ -5996,6 +5997,7 @@ void __init sched_init(void)
for_each_possible_cpu(i) {
struct rq *rq;
+ per_cpu(next_cpu, i) = -1;
rq = cpu_rq(i);
raw_spin_lock_init(&rq->lock);
rq->nr_running = 0;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 67702b4..eb12b50 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -912,6 +912,7 @@ static inline void update_idle_core(struct rq *rq) { }
#endif
DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
+DECLARE_PER_CPU_SHARED_ALIGNED(int, next_cpu);
#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
#define this_rq() this_cpu_ptr(&runqueues)
--
2.9.3