[PATCH 2/3] sched: Convert paravirt_steal to new static key APIs

From: Hongyan Xia <hidden>
Date: 2026-07-20 09:38:16
Also in: kvm, linux-arm-kernel, linux-riscv, lkml, loongarch, virtualization, xen-devel
Subsystem: arm64 port (aarch64 architecture), kvm paravirt (kvm/paravirt), linux for powerpc (32-bit and 64-bit), loongarch, paravirt_ops interface, risc-v architecture, scheduler, the rest, vmware hypervisor interface, x86 architecture (32-bit and 64-bit), xen hypervisor interface · Maintainers: Catalin Marinas, Will Deacon, Paolo Bonzini, Madhavan Srinivasan, Michael Ellerman, Huacai Chen, Juergen Gross, Paul Walmsley, Palmer Dabbelt, Albert Ou, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds, Ajay Kaher, Alexey Makhalov, Thomas Gleixner, Borislav Petkov, Dave Hansen, Stefano Stabellini

From: Hongyan Xia <redacted>

paravirt_steal_rq_enabled and paravirt_steal_enabled use raw static_key
APIs which are now deprecated. Use the new API instead.

No functional change.

Signed-off-by: Hongyan Xia <redacted>
---
 arch/arm64/kernel/paravirt.c           | 4 ++--
 arch/loongarch/kernel/paravirt.c       | 4 ++--
 arch/powerpc/platforms/pseries/setup.c | 4 ++--
 arch/riscv/kernel/paravirt.c           | 4 ++--
 arch/x86/kernel/cpu/vmware.c           | 4 ++--
 arch/x86/kernel/kvm.c                  | 4 ++--
 drivers/xen/time.c                     | 4 ++--
 include/linux/sched/cputime.h          | 6 +++---
 kernel/sched/core.c                    | 4 ++--
 kernel/sched/cputime.c                 | 4 ++--
 10 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c
index 572efb96b23f..30bf61d031eb 100644
--- a/arch/arm64/kernel/paravirt.c
+++ b/arch/arm64/kernel/paravirt.c

@@ -157,9 +157,9 @@ int __init pv_time_init(void)
 
 	static_call_update(pv_steal_clock, para_steal_clock);
 
-	static_key_slow_inc(&paravirt_steal_enabled);
+	static_branch_inc(&paravirt_steal_enabled);
 	if (steal_acc)
-		static_key_slow_inc(&paravirt_steal_rq_enabled);
+		static_branch_inc(&paravirt_steal_rq_enabled);
 
 	pr_info("using stolen time PV\n");

diff --git a/arch/loongarch/kernel/paravirt.c b/arch/loongarch/kernel/paravirt.c
index 10821cce554c..e8965a3f8082 100644
--- a/arch/loongarch/kernel/paravirt.c
+++ b/arch/loongarch/kernel/paravirt.c

@@ -308,10 +308,10 @@ int __init pv_time_init(void)
 
 	static_call_update(pv_steal_clock, paravt_steal_clock);
 
-	static_key_slow_inc(&paravirt_steal_enabled);
+	static_branch_inc(&paravirt_steal_enabled);
 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
 	if (steal_acc)
-		static_key_slow_inc(&paravirt_steal_rq_enabled);
+		static_branch_inc(&paravirt_steal_rq_enabled);
 #endif
 
 	if (static_key_enabled(&virt_preempt_key))

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 1223dc961242..8dcbc4bb7025 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c

@@ -852,9 +852,9 @@ static void __init pSeries_setup_arch(void)
 			static_branch_enable(&shared_processor);
 			pv_spinlocks_init();
 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
-			static_key_slow_inc(&paravirt_steal_enabled);
+			static_branch_inc(&paravirt_steal_enabled);
 			if (steal_acc)
-				static_key_slow_inc(&paravirt_steal_rq_enabled);
+				static_branch_inc(&paravirt_steal_rq_enabled);
 #endif
 		}

diff --git a/arch/riscv/kernel/paravirt.c b/arch/riscv/kernel/paravirt.c
index 5f56be79cd06..9c13a6f1ea2a 100644
--- a/arch/riscv/kernel/paravirt.c
+++ b/arch/riscv/kernel/paravirt.c

@@ -116,9 +116,9 @@ int __init pv_time_init(void)
 
 	static_call_update(pv_steal_clock, pv_time_steal_clock);
 
-	static_key_slow_inc(&paravirt_steal_enabled);
+	static_branch_inc(&paravirt_steal_enabled);
 	if (steal_acc)
-		static_key_slow_inc(&paravirt_steal_rq_enabled);
+		static_branch_inc(&paravirt_steal_rq_enabled);
 
 	pr_info("Computing paravirt steal-time\n");

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 34b73573b108..f7ab9e7902cf 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c

@@ -328,9 +328,9 @@ static int vmware_cpu_down_prepare(unsigned int cpu)
 static __init int activate_jump_labels(void)
 {
 	if (has_steal_clock) {
-		static_key_slow_inc(&paravirt_steal_enabled);
+		static_branch_inc(&paravirt_steal_enabled);
 		if (steal_acc)
-			static_key_slow_inc(&paravirt_steal_rq_enabled);
+			static_branch_inc(&paravirt_steal_rq_enabled);
 	}
 
 	return 0;

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index dcef84da304b..d3dcd64f22c2 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c

@@ -1052,9 +1052,9 @@ const __initconst struct hypervisor_x86 x86_hyper_kvm = {
 static __init int activate_jump_labels(void)
 {
 	if (has_steal_clock) {
-		static_key_slow_inc(&paravirt_steal_enabled);
+		static_branch_inc(&paravirt_steal_enabled);
 		if (steal_acc)
-			static_key_slow_inc(&paravirt_steal_rq_enabled);
+			static_branch_inc(&paravirt_steal_rq_enabled);
 	}
 
 	return 0;

diff --git a/drivers/xen/time.c b/drivers/xen/time.c
index a2be0a4d45b0..a02d48a2aa68 100644
--- a/drivers/xen/time.c
+++ b/drivers/xen/time.c

@@ -169,7 +169,7 @@ void __init xen_time_setup_guest(void)
 
 	static_call_update(pv_steal_clock, xen_steal_clock);
 
-	static_key_slow_inc(&paravirt_steal_enabled);
+	static_branch_inc(&paravirt_steal_enabled);
 	if (xen_runstate_remote)
-		static_key_slow_inc(&paravirt_steal_rq_enabled);
+		static_branch_inc(&paravirt_steal_rq_enabled);
 }

diff --git a/include/linux/sched/cputime.h b/include/linux/sched/cputime.h
index e90efaf6d26e..694126411dfe 100644
--- a/include/linux/sched/cputime.h
+++ b/include/linux/sched/cputime.h

@@ -182,9 +182,9 @@ extern unsigned long long
 task_sched_runtime(struct task_struct *task);
 
 #ifdef CONFIG_PARAVIRT
-struct static_key;
-extern struct static_key paravirt_steal_enabled;
-extern struct static_key paravirt_steal_rq_enabled;
+#include <linux/jump_label.h>
+DECLARE_STATIC_KEY_FALSE(paravirt_steal_enabled);
+DECLARE_STATIC_KEY_FALSE(paravirt_steal_rq_enabled);
 
 #ifdef CONFIG_HAVE_PV_STEAL_CLOCK_GEN
 u64 dummy_steal_clock(int cpu);

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 96226707c2f6..786975d4ca1e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c

@@ -795,7 +795,7 @@ struct rq *_task_rq_lock(struct task_struct *p, struct rq_flags *rf)
 
 /* Use CONFIG_PARAVIRT as this will avoid more #ifdef in arch code. */
 #ifdef CONFIG_PARAVIRT
-struct static_key paravirt_steal_rq_enabled;
+DEFINE_STATIC_KEY_FALSE(paravirt_steal_rq_enabled);
 #endif
 
 static void update_rq_clock_task(struct rq *rq, s64 delta)

@@ -834,7 +834,7 @@ static void update_rq_clock_task(struct rq *rq, s64 delta)
 	}
 #endif
 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
-	if (static_key_false((&paravirt_steal_rq_enabled))) {
+	if (static_branch_unlikely(&paravirt_steal_rq_enabled)) {
 		u64 prev_steal;
 
 		steal = prev_steal = paravirt_steal_clock(cpu_of(rq));

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 06bddaa738e5..f16970ca81d0 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c

@@ -255,7 +255,7 @@ void __account_forceidle_time(struct task_struct *p, u64 delta)
  * occasion account more time than the calling functions think elapsed.
  */
 #ifdef CONFIG_PARAVIRT
-struct static_key paravirt_steal_enabled;
+DEFINE_STATIC_KEY_FALSE(paravirt_steal_enabled);
 
 #ifdef CONFIG_HAVE_PV_STEAL_CLOCK_GEN
 static u64 native_steal_clock(int cpu)

@@ -270,7 +270,7 @@ DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
 static __always_inline u64 steal_account_process_time(u64 maxtime)
 {
 #ifdef CONFIG_PARAVIRT
-	if (static_key_false(&paravirt_steal_enabled)) {
+	if (static_branch_unlikely(&paravirt_steal_enabled)) {
 		u64 steal;
 
 		steal = paravirt_steal_clock(smp_processor_id());

-- 
2.47.3

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