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-rw-r--r--include/linux/hardirq.h15
-rw-r--r--include/linux/kernel_stat.h9
-rw-r--r--include/linux/kvm_host.h12
-rw-r--r--include/linux/vtime.h47
4 files changed, 61 insertions, 22 deletions
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index cab3da3d0949..624ef3f45c8e 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -4,6 +4,7 @@
#include <linux/preempt.h>
#include <linux/lockdep.h>
#include <linux/ftrace_irq.h>
+#include <linux/vtime.h>
#include <asm/hardirq.h>
/*
@@ -129,16 +130,6 @@ extern void synchronize_irq(unsigned int irq);
# define synchronize_irq(irq) barrier()
#endif
-struct task_struct;
-
-#if !defined(CONFIG_VIRT_CPU_ACCOUNTING) && !defined(CONFIG_IRQ_TIME_ACCOUNTING)
-static inline void vtime_account(struct task_struct *tsk)
-{
-}
-#else
-extern void vtime_account(struct task_struct *tsk);
-#endif
-
#if defined(CONFIG_TINY_RCU) || defined(CONFIG_TINY_PREEMPT_RCU)
static inline void rcu_nmi_enter(void)
@@ -162,7 +153,7 @@ extern void rcu_nmi_exit(void);
*/
#define __irq_enter() \
do { \
- vtime_account(current); \
+ vtime_account_irq_enter(current); \
add_preempt_count(HARDIRQ_OFFSET); \
trace_hardirq_enter(); \
} while (0)
@@ -178,7 +169,7 @@ extern void irq_enter(void);
#define __irq_exit() \
do { \
trace_hardirq_exit(); \
- vtime_account(current); \
+ vtime_account_irq_exit(current); \
sub_preempt_count(HARDIRQ_OFFSET); \
} while (0)
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 36d12f0884c3..1865b1f29770 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -7,6 +7,7 @@
#include <linux/cpumask.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
+#include <linux/vtime.h>
#include <asm/irq.h>
#include <asm/cputime.h>
@@ -130,12 +131,4 @@ extern void account_process_tick(struct task_struct *, int user);
extern void account_steal_ticks(unsigned long ticks);
extern void account_idle_ticks(unsigned long ticks);
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-extern void vtime_task_switch(struct task_struct *prev);
-extern void vtime_account_system(struct task_struct *tsk);
-extern void vtime_account_idle(struct task_struct *tsk);
-#else
-static inline void vtime_task_switch(struct task_struct *prev) { }
-#endif
-
#endif /* _LINUX_KERNEL_STAT_H */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 93bfc9f9815c..0e2212fe4784 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -737,7 +737,11 @@ static inline int kvm_deassign_device(struct kvm *kvm,
static inline void kvm_guest_enter(void)
{
BUG_ON(preemptible());
- vtime_account(current);
+ /*
+ * This is running in ioctl context so we can avoid
+ * the call to vtime_account() with its unnecessary idle check.
+ */
+ vtime_account_system(current);
current->flags |= PF_VCPU;
/* KVM does not hold any references to rcu protected data when it
* switches CPU into a guest mode. In fact switching to a guest mode
@@ -751,7 +755,11 @@ static inline void kvm_guest_enter(void)
static inline void kvm_guest_exit(void)
{
- vtime_account(current);
+ /*
+ * This is running in ioctl context so we can avoid
+ * the call to vtime_account() with its unnecessary idle check.
+ */
+ vtime_account_system(current);
current->flags &= ~PF_VCPU;
}
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
new file mode 100644
index 000000000000..0c2a2d303020
--- /dev/null
+++ b/include/linux/vtime.h
@@ -0,0 +1,47 @@
+#ifndef _LINUX_KERNEL_VTIME_H
+#define _LINUX_KERNEL_VTIME_H
+
+struct task_struct;
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+extern void vtime_task_switch(struct task_struct *prev);
+extern void __vtime_account_system(struct task_struct *tsk);
+extern void vtime_account_system(struct task_struct *tsk);
+extern void __vtime_account_idle(struct task_struct *tsk);
+extern void vtime_account(struct task_struct *tsk);
+#else
+static inline void vtime_task_switch(struct task_struct *prev) { }
+static inline void __vtime_account_system(struct task_struct *tsk) { }
+static inline void vtime_account_system(struct task_struct *tsk) { }
+static inline void vtime_account(struct task_struct *tsk) { }
+#endif
+
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
+extern void irqtime_account_irq(struct task_struct *tsk);
+#else
+static inline void irqtime_account_irq(struct task_struct *tsk) { }
+#endif
+
+static inline void vtime_account_irq_enter(struct task_struct *tsk)
+{
+ /*
+ * Hardirq can interrupt idle task anytime. So we need vtime_account()
+ * that performs the idle check in CONFIG_VIRT_CPU_ACCOUNTING.
+ * Softirq can also interrupt idle task directly if it calls
+ * local_bh_enable(). Such case probably don't exist but we never know.
+ * Ksoftirqd is not concerned because idle time is flushed on context
+ * switch. Softirqs in the end of hardirqs are also not a problem because
+ * the idle time is flushed on hardirq time already.
+ */
+ vtime_account(tsk);
+ irqtime_account_irq(tsk);
+}
+
+static inline void vtime_account_irq_exit(struct task_struct *tsk)
+{
+ /* On hard|softirq exit we always account to hard|softirq cputime */
+ __vtime_account_system(tsk);
+ irqtime_account_irq(tsk);
+}
+
+#endif /* _LINUX_KERNEL_VTIME_H */