[PATCH v3 5/9] sched/vtime: Move guest enter/exit vtime accounting to vtime.h

From: Sean Christopherson
Date: Thu Apr 15 2021 - 18:21:39 EST


Provide separate helpers for guest enter vtime accounting (in addition to
the existing guest exit helpers), and move all vtime accounting helpers
to vtime.h where the existing #ifdef infrastructure can be leveraged to
better delineate the different types of accounting. This will also allow
future cleanups via deduplication of context tracking code.

Opportunstically delete the vtime_account_kernel() stub now that all
callers are wrapped with CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
include/linux/context_tracking.h | 17 +-----------
include/linux/vtime.h | 46 +++++++++++++++++++++++++++-----
2 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 7cf03a8e5708..1c05035396ad 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -137,14 +137,6 @@ static __always_inline void context_tracking_guest_exit_irqoff(void)
__context_tracking_exit(CONTEXT_GUEST);
}

-static __always_inline void vtime_account_guest_exit(void)
-{
- if (vtime_accounting_enabled_this_cpu())
- vtime_guest_exit(current);
- else
- current->flags &= ~PF_VCPU;
-}
-
static __always_inline void guest_exit_irqoff(void)
{
context_tracking_guest_exit_irqoff();
@@ -163,20 +155,13 @@ static __always_inline void guest_enter_irqoff(void)
* to flush.
*/
instrumentation_begin();
- vtime_account_kernel(current);
- current->flags |= PF_VCPU;
+ vtime_account_guest_enter();
rcu_virt_note_context_switch(smp_processor_id());
instrumentation_end();
}

static __always_inline void context_tracking_guest_exit_irqoff(void) { }

-static __always_inline void vtime_account_guest_exit(void)
-{
- vtime_account_kernel(current);
- current->flags &= ~PF_VCPU;
-}
-
static __always_inline void guest_exit_irqoff(void)
{
instrumentation_begin();
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index 6a4317560539..3684487d01e1 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -3,21 +3,18 @@
#define _LINUX_KERNEL_VTIME_H

#include <linux/context_tracking_state.h>
+#include <linux/sched.h>
+
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
#include <asm/vtime.h>
#endif

-
-struct task_struct;
-
/*
* Common vtime APIs
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
extern void vtime_account_kernel(struct task_struct *tsk);
extern void vtime_account_idle(struct task_struct *tsk);
-#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
-static inline void vtime_account_kernel(struct task_struct *tsk) { }
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
@@ -55,6 +52,18 @@ static inline void vtime_flush(struct task_struct *tsk) { }
static inline bool vtime_accounting_enabled_this_cpu(void) { return true; }
extern void vtime_task_switch(struct task_struct *prev);

+static __always_inline void vtime_account_guest_enter(void)
+{
+ vtime_account_kernel(current);
+ current->flags |= PF_VCPU;
+}
+
+static __always_inline void vtime_account_guest_exit(void)
+{
+ vtime_account_kernel(current);
+ current->flags &= ~PF_VCPU;
+}
+
#elif defined(CONFIG_VIRT_CPU_ACCOUNTING_GEN)

/*
@@ -86,12 +95,37 @@ static inline void vtime_task_switch(struct task_struct *prev)
vtime_task_switch_generic(prev);
}

+static __always_inline void vtime_account_guest_enter(void)
+{
+ if (vtime_accounting_enabled_this_cpu())
+ vtime_guest_enter(current);
+ else
+ current->flags |= PF_VCPU;
+}
+
+static __always_inline void vtime_account_guest_exit(void)
+{
+ if (vtime_accounting_enabled_this_cpu())
+ vtime_guest_exit(current);
+ else
+ current->flags &= ~PF_VCPU;
+}
+
#else /* !CONFIG_VIRT_CPU_ACCOUNTING */

-static inline bool vtime_accounting_enabled_cpu(int cpu) {return false; }
static inline bool vtime_accounting_enabled_this_cpu(void) { return false; }
static inline void vtime_task_switch(struct task_struct *prev) { }

+static __always_inline void vtime_account_guest_enter(void)
+{
+ current->flags |= PF_VCPU;
+}
+
+static __always_inline void vtime_account_guest_exit(void)
+{
+ current->flags &= ~PF_VCPU;
+}
+
#endif


--
2.31.1.368.gbe11c130af-goog