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-rw-r--r--include/linux/context_tracking.h128
1 files changed, 69 insertions, 59 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index fc09d7b0dacf..158158704c30 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -2,100 +2,110 @@
#define _LINUX_CONTEXT_TRACKING_H
#include <linux/sched.h>
-#include <linux/percpu.h>
#include <linux/vtime.h>
+#include <linux/context_tracking_state.h>
#include <asm/ptrace.h>
-struct context_tracking {
- /*
- * When active is false, probes are unset in order
- * to minimize overhead: TIF flags are cleared
- * and calls to user_enter/exit are ignored. This
- * may be further optimized using static keys.
- */
- bool active;
- enum ctx_state {
- IN_KERNEL = 0,
- IN_USER,
- } state;
-};
-
-static inline void __guest_enter(void)
-{
- /*
- * 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;
-}
-
-static inline void __guest_exit(void)
-{
- /*
- * 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;
-}
#ifdef CONFIG_CONTEXT_TRACKING
-DECLARE_PER_CPU(struct context_tracking, context_tracking);
+extern void context_tracking_cpu_set(int cpu);
-static inline bool context_tracking_in_user(void)
+extern void context_tracking_user_enter(void);
+extern void context_tracking_user_exit(void);
+extern void __context_tracking_task_switch(struct task_struct *prev,
+ struct task_struct *next);
+
+static inline void user_enter(void)
{
- return __this_cpu_read(context_tracking.state) == IN_USER;
-}
+ if (static_key_false(&context_tracking_enabled))
+ context_tracking_user_enter();
-static inline bool context_tracking_active(void)
+}
+static inline void user_exit(void)
{
- return __this_cpu_read(context_tracking.active);
+ if (static_key_false(&context_tracking_enabled))
+ context_tracking_user_exit();
}
-extern void user_enter(void);
-extern void user_exit(void);
-
-extern void guest_enter(void);
-extern void guest_exit(void);
-
static inline enum ctx_state exception_enter(void)
{
enum ctx_state prev_ctx;
+ if (!static_key_false(&context_tracking_enabled))
+ return 0;
+
prev_ctx = this_cpu_read(context_tracking.state);
- user_exit();
+ context_tracking_user_exit();
return prev_ctx;
}
static inline void exception_exit(enum ctx_state prev_ctx)
{
- if (prev_ctx == IN_USER)
- user_enter();
+ if (static_key_false(&context_tracking_enabled)) {
+ if (prev_ctx == IN_USER)
+ context_tracking_user_enter();
+ }
}
-extern void context_tracking_task_switch(struct task_struct *prev,
- struct task_struct *next);
+static inline void context_tracking_task_switch(struct task_struct *prev,
+ struct task_struct *next)
+{
+ if (static_key_false(&context_tracking_enabled))
+ __context_tracking_task_switch(prev, next);
+}
#else
-static inline bool context_tracking_in_user(void) { return false; }
static inline void user_enter(void) { }
static inline void user_exit(void) { }
+static inline enum ctx_state exception_enter(void) { return 0; }
+static inline void exception_exit(enum ctx_state prev_ctx) { }
+static inline void context_tracking_task_switch(struct task_struct *prev,
+ struct task_struct *next) { }
+#endif /* !CONFIG_CONTEXT_TRACKING */
+
+
+#ifdef CONFIG_CONTEXT_TRACKING_FORCE
+extern void context_tracking_init(void);
+#else
+static inline void context_tracking_init(void) { }
+#endif /* CONFIG_CONTEXT_TRACKING_FORCE */
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
static inline void guest_enter(void)
{
- __guest_enter();
+ if (vtime_accounting_enabled())
+ vtime_guest_enter(current);
+ else
+ current->flags |= PF_VCPU;
}
static inline void guest_exit(void)
{
- __guest_exit();
+ if (vtime_accounting_enabled())
+ vtime_guest_exit(current);
+ else
+ current->flags &= ~PF_VCPU;
}
-static inline enum ctx_state exception_enter(void) { return 0; }
-static inline void exception_exit(enum ctx_state prev_ctx) { }
-static inline void context_tracking_task_switch(struct task_struct *prev,
- struct task_struct *next) { }
-#endif /* !CONFIG_CONTEXT_TRACKING */
+#else
+static inline void guest_enter(void)
+{
+ /*
+ * This is running in ioctl context so its safe
+ * to assume that it's the stime pending cputime
+ * to flush.
+ */
+ vtime_account_system(current);
+ current->flags |= PF_VCPU;
+}
+
+static inline void guest_exit(void)
+{
+ /* Flush the guest cputime we spent on the guest */
+ vtime_account_system(current);
+ current->flags &= ~PF_VCPU;
+}
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
#endif