[PATCH 3/3] LoongArch: Add paravirt preempt hint print prompt

Bibo Mao posted 3 patches 1 week, 6 days ago
[PATCH 3/3] LoongArch: Add paravirt preempt hint print prompt
Posted by Bibo Mao 1 week, 6 days ago
Add paravirt preempt hint print prompt together with steal timer
information, so that it is easy to check whether paravirt preempt hint
feature is enabled or not.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 arch/loongarch/kernel/paravirt.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/loongarch/kernel/paravirt.c b/arch/loongarch/kernel/paravirt.c
index b99404b6b13f..b7ea511c288b 100644
--- a/arch/loongarch/kernel/paravirt.c
+++ b/arch/loongarch/kernel/paravirt.c
@@ -294,6 +294,7 @@ static struct notifier_block pv_reboot_nb = {
 int __init pv_time_init(void)
 {
 	int r;
+	bool pv_preempted = false;
 
 	if (!kvm_para_has_feature(KVM_FEATURE_STEAL_TIME))
 		return 0;
@@ -316,8 +317,10 @@ int __init pv_time_init(void)
 		return r;
 	}
 
-	if (kvm_para_has_feature(KVM_FEATURE_PREEMPT_HINT))
+	if (kvm_para_has_feature(KVM_FEATURE_PREEMPT_HINT)) {
 		mp_ops.vcpu_is_preempted = pv_vcpu_is_preempted;
+		pv_preempted = true;
+	}
 #endif
 
 	static_call_update(pv_steal_clock, paravt_steal_clock);
@@ -328,7 +331,10 @@ int __init pv_time_init(void)
 		static_key_slow_inc(&paravirt_steal_rq_enabled);
 #endif
 
-	pr_info("Using paravirt steal-time\n");
+	if (pv_preempted)
+		pr_info("Using paravirt steal-time with preempt hint enabled\n");
+	else
+		pr_info("Using paravirt steal-time with preempt hint disabled\n");
 
 	return 0;
 }
-- 
2.39.3