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-rw-r--r--kernel/sched.c30
-rw-r--r--kernel/sched_features.h3
-rw-r--r--kernel/sysctl.c8
3 files changed, 39 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 1cff969..62db089 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -778,6 +778,12 @@ late_initcall(sched_init_debug);
const_debug unsigned int sysctl_sched_nr_migrate = 32;
/*
+ * ratelimit for updating the group shares.
+ * default: 0.5ms
+ */
+const_debug unsigned int sysctl_sched_shares_ratelimit = 500000;
+
+/*
* period over which we measure -rt task cpu usage in us.
* default: 1s
*/
@@ -1590,7 +1596,13 @@ tg_nop(struct task_group *tg, int cpu, struct sched_domain *sd)
static void update_shares(struct sched_domain *sd)
{
- walk_tg_tree(tg_nop, tg_shares_up, 0, sd);
+ u64 now = cpu_clock(raw_smp_processor_id());
+ s64 elapsed = now - sd->last_update;
+
+ if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
+ sd->last_update = now;
+ walk_tg_tree(tg_nop, tg_shares_up, 0, sd);
+ }
}
static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
@@ -2199,6 +2211,22 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (!sched_feat(SYNC_WAKEUPS))
sync = 0;
+#ifdef CONFIG_SMP
+ if (sched_feat(LB_WAKEUP_UPDATE)) {
+ struct sched_domain *sd;
+
+ this_cpu = raw_smp_processor_id();
+ cpu = task_cpu(p);
+
+ for_each_domain(this_cpu, sd) {
+ if (cpu_isset(cpu, sd->span)) {
+ update_shares(sd);
+ break;
+ }
+ }
+ }
+#endif
+
smp_wmb();
rq = task_rq_lock(p, &flags);
old_state = p->state;
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index d56e305..7d616d2 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -8,4 +8,5 @@ SCHED_FEAT(SYNC_WAKEUPS, 1)
SCHED_FEAT(HRTICK, 1)
SCHED_FEAT(DOUBLE_TICK, 0)
SCHED_FEAT(ASYM_GRAN, 1)
-SCHED_FEAT(LB_BIAS, 0) \ No newline at end of file
+SCHED_FEAT(LB_BIAS, 0)
+SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 2911665..fe8cdc8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -266,6 +266,14 @@ static struct ctl_table kern_table[] = {
},
{
.ctl_name = CTL_UNNUMBERED,
+ .procname = "sched_shares_ratelimit",
+ .data = &sysctl_sched_shares_ratelimit,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
.procname = "sched_child_runs_first",
.data = &sysctl_sched_child_runs_first,
.maxlen = sizeof(unsigned int),