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-rw-r--r--arch/Kconfig37
-rw-r--r--arch/arm/include/asm/paravirt_api_clock.h1
-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/include/asm/paravirt_api_clock.h1
-rw-r--r--arch/arm64/include/asm/preempt.h19
-rw-r--r--arch/arm64/kernel/entry-common.c28
-rw-r--r--arch/x86/Kconfig2
-rw-r--r--arch/x86/include/asm/paravirt_api_clock.h1
-rw-r--r--arch/x86/include/asm/preempt.h10
-rw-r--r--arch/x86/kernel/cpu/aperfmperf.c6
-rw-r--r--arch/x86/kvm/x86.c2
11 files changed, 84 insertions, 24 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index cabfac22f2fb..17709ac1030a 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1293,12 +1293,41 @@ config HAVE_STATIC_CALL_INLINE
config HAVE_PREEMPT_DYNAMIC
bool
+
+config HAVE_PREEMPT_DYNAMIC_CALL
+ bool
depends on HAVE_STATIC_CALL
- depends on GENERIC_ENTRY
+ select HAVE_PREEMPT_DYNAMIC
+ help
+ An architecture should select this if it can handle the preemption
+ model being selected at boot time using static calls.
+
+ Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a
+ preemption function will be patched directly.
+
+ Where an architecture does not select HAVE_STATIC_CALL_INLINE, any
+ call to a preemption function will go through a trampoline, and the
+ trampoline will be patched.
+
+ It is strongly advised to support inline static call to avoid any
+ overhead.
+
+config HAVE_PREEMPT_DYNAMIC_KEY
+ bool
+ depends on HAVE_ARCH_JUMP_LABEL && CC_HAS_ASM_GOTO
+ select HAVE_PREEMPT_DYNAMIC
help
- Select this if the architecture support boot time preempt setting
- on top of static calls. It is strongly advised to support inline
- static call to avoid any overhead.
+ An architecture should select this if it can handle the preemption
+ model being selected at boot time using static keys.
+
+ Each preemption function will be given an early return based on a
+ static key. This should have slightly lower overhead than non-inline
+ static calls, as this effectively inlines each trampoline into the
+ start of its callee. This may avoid redundant work, and may
+ integrate better with CFI schemes.
+
+ This will have greater overhead than using inline static calls as
+ the call to the preemption function cannot be entirely elided.
config ARCH_WANT_LD_ORPHAN_WARN
bool
diff --git a/arch/arm/include/asm/paravirt_api_clock.h b/arch/arm/include/asm/paravirt_api_clock.h
new file mode 100644
index 000000000000..65ac7cee0dad
--- /dev/null
+++ b/arch/arm/include/asm/paravirt_api_clock.h
@@ -0,0 +1 @@
+#include <asm/paravirt.h>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 8c54de0cf3d6..13aa8d955c46 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -194,6 +194,7 @@ config ARM64
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
+ select HAVE_PREEMPT_DYNAMIC_KEY
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_POSIX_CPU_TIMERS_TASK_WORK
select HAVE_FUNCTION_ARG_ACCESS_API
diff --git a/arch/arm64/include/asm/paravirt_api_clock.h b/arch/arm64/include/asm/paravirt_api_clock.h
new file mode 100644
index 000000000000..65ac7cee0dad
--- /dev/null
+++ b/arch/arm64/include/asm/paravirt_api_clock.h
@@ -0,0 +1 @@
+#include <asm/paravirt.h>
diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index e83f0982b99c..0159b625cc7f 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -2,6 +2,7 @@
#ifndef __ASM_PREEMPT_H
#define __ASM_PREEMPT_H
+#include <linux/jump_label.h>
#include <linux/thread_info.h>
#define PREEMPT_NEED_RESCHED BIT(32)
@@ -80,10 +81,24 @@ static inline bool should_resched(int preempt_offset)
}
#ifdef CONFIG_PREEMPTION
+
void preempt_schedule(void);
-#define __preempt_schedule() preempt_schedule()
void preempt_schedule_notrace(void);
-#define __preempt_schedule_notrace() preempt_schedule_notrace()
+
+#ifdef CONFIG_PREEMPT_DYNAMIC
+
+DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
+void dynamic_preempt_schedule(void);
+#define __preempt_schedule() dynamic_preempt_schedule()
+void dynamic_preempt_schedule_notrace(void);
+#define __preempt_schedule_notrace() dynamic_preempt_schedule_notrace()
+
+#else /* CONFIG_PREEMPT_DYNAMIC */
+
+#define __preempt_schedule() preempt_schedule()
+#define __preempt_schedule_notrace() preempt_schedule_notrace()
+
+#endif /* CONFIG_PREEMPT_DYNAMIC */
#endif /* CONFIG_PREEMPTION */
#endif /* __ASM_PREEMPT_H */
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 7093b578e325..878c65aa7206 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -223,9 +223,26 @@ static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs)
lockdep_hardirqs_on(CALLER_ADDR0);
}
+#ifdef CONFIG_PREEMPT_DYNAMIC
+DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
+#define need_irq_preemption() \
+ (static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched))
+#else
+#define need_irq_preemption() (IS_ENABLED(CONFIG_PREEMPTION))
+#endif
+
static void __sched arm64_preempt_schedule_irq(void)
{
- lockdep_assert_irqs_disabled();
+ if (!need_irq_preemption())
+ return;
+
+ /*
+ * Note: thread_info::preempt_count includes both thread_info::count
+ * and thread_info::need_resched, and is not equivalent to
+ * preempt_count().
+ */
+ if (READ_ONCE(current_thread_info()->preempt_count) != 0)
+ return;
/*
* DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC
@@ -441,14 +458,7 @@ static __always_inline void __el1_irq(struct pt_regs *regs,
do_interrupt_handler(regs, handler);
irq_exit_rcu();
- /*
- * Note: thread_info::preempt_count includes both thread_info::count
- * and thread_info::need_resched, and is not equivalent to
- * preempt_count().
- */
- if (IS_ENABLED(CONFIG_PREEMPTION) &&
- READ_ONCE(current_thread_info()->preempt_count) == 0)
- arm64_preempt_schedule_irq();
+ arm64_preempt_schedule_irq();
exit_to_kernel_mode(regs);
}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 327e045540fa..42a3a736436f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -248,7 +248,7 @@ config X86
select HAVE_STACK_VALIDATION if X86_64
select HAVE_STATIC_CALL
select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION
- select HAVE_PREEMPT_DYNAMIC
+ select HAVE_PREEMPT_DYNAMIC_CALL
select HAVE_RSEQ
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UNSTABLE_SCHED_CLOCK
diff --git a/arch/x86/include/asm/paravirt_api_clock.h b/arch/x86/include/asm/paravirt_api_clock.h
new file mode 100644
index 000000000000..65ac7cee0dad
--- /dev/null
+++ b/arch/x86/include/asm/paravirt_api_clock.h
@@ -0,0 +1 @@
+#include <asm/paravirt.h>
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index fe5efbcba824..5f6daea1ee24 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -108,16 +108,18 @@ static __always_inline bool should_resched(int preempt_offset)
extern asmlinkage void preempt_schedule(void);
extern asmlinkage void preempt_schedule_thunk(void);
-#define __preempt_schedule_func preempt_schedule_thunk
+#define preempt_schedule_dynamic_enabled preempt_schedule_thunk
+#define preempt_schedule_dynamic_disabled NULL
extern asmlinkage void preempt_schedule_notrace(void);
extern asmlinkage void preempt_schedule_notrace_thunk(void);
-#define __preempt_schedule_notrace_func preempt_schedule_notrace_thunk
+#define preempt_schedule_notrace_dynamic_enabled preempt_schedule_notrace_thunk
+#define preempt_schedule_notrace_dynamic_disabled NULL
#ifdef CONFIG_PREEMPT_DYNAMIC
-DECLARE_STATIC_CALL(preempt_schedule, __preempt_schedule_func);
+DECLARE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled);
#define __preempt_schedule() \
do { \
@@ -125,7 +127,7 @@ do { \
asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule) : ASM_CALL_CONSTRAINT); \
} while (0)
-DECLARE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func);
+DECLARE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled);
#define __preempt_schedule_notrace() \
do { \
diff --git a/arch/x86/kernel/cpu/aperfmperf.c b/arch/x86/kernel/cpu/aperfmperf.c
index 22911deacb6e..9ca008f9e9b1 100644
--- a/arch/x86/kernel/cpu/aperfmperf.c
+++ b/arch/x86/kernel/cpu/aperfmperf.c
@@ -91,7 +91,7 @@ unsigned int aperfmperf_get_khz(int cpu)
if (!boot_cpu_has(X86_FEATURE_APERFMPERF))
return 0;
- if (!housekeeping_cpu(cpu, HK_FLAG_MISC))
+ if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
return 0;
if (rcu_is_idle_cpu(cpu))
@@ -114,7 +114,7 @@ void arch_freq_prepare_all(void)
return;
for_each_online_cpu(cpu) {
- if (!housekeeping_cpu(cpu, HK_FLAG_MISC))
+ if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
continue;
if (rcu_is_idle_cpu(cpu))
continue; /* Idle CPUs are completely uninteresting. */
@@ -136,7 +136,7 @@ unsigned int arch_freq_get_on_cpu(int cpu)
if (!boot_cpu_has(X86_FEATURE_APERFMPERF))
return 0;
- if (!housekeeping_cpu(cpu, HK_FLAG_MISC))
+ if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
return 0;
if (aperfmperf_snapshot_cpu(cpu, ktime_get(), true))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eb8269a4c83c..6db3a506b402 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8853,7 +8853,7 @@ int kvm_arch_init(void *opaque)
}
if (pi_inject_timer == -1)
- pi_inject_timer = housekeeping_enabled(HK_FLAG_TIMER);
+ pi_inject_timer = housekeeping_enabled(HK_TYPE_TIMER);
#ifdef CONFIG_X86_64
pvclock_gtod_register_notifier(&pvclock_gtod_notifier);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-27 23:13:58 +0000