https://github.com/torvalds/linux
Tip revision: 74bf8efb5fa6e958d2d7c7917b8bb672085ec0c6 authored by Linus Torvalds on 28 December 2015, 02:17:37 UTC
Linux 4.4-rc7
Linux 4.4-rc7
Tip revision: 74bf8ef
context_tracking.h
#ifndef _LINUX_CONTEXT_TRACKING_H
#define _LINUX_CONTEXT_TRACKING_H
#include <linux/sched.h>
#include <linux/vtime.h>
#include <linux/context_tracking_state.h>
#include <asm/ptrace.h>
#ifdef CONFIG_CONTEXT_TRACKING
extern void context_tracking_cpu_set(int cpu);
/* Called with interrupts disabled. */
extern void __context_tracking_enter(enum ctx_state state);
extern void __context_tracking_exit(enum ctx_state state);
extern void context_tracking_enter(enum ctx_state state);
extern void context_tracking_exit(enum ctx_state state);
extern void context_tracking_user_enter(void);
extern void context_tracking_user_exit(void);
static inline void user_enter(void)
{
if (context_tracking_is_enabled())
context_tracking_enter(CONTEXT_USER);
}
static inline void user_exit(void)
{
if (context_tracking_is_enabled())
context_tracking_exit(CONTEXT_USER);
}
static inline enum ctx_state exception_enter(void)
{
enum ctx_state prev_ctx;
if (!context_tracking_is_enabled())
return 0;
prev_ctx = this_cpu_read(context_tracking.state);
if (prev_ctx != CONTEXT_KERNEL)
context_tracking_exit(prev_ctx);
return prev_ctx;
}
static inline void exception_exit(enum ctx_state prev_ctx)
{
if (context_tracking_is_enabled()) {
if (prev_ctx != CONTEXT_KERNEL)
context_tracking_enter(prev_ctx);
}
}
/**
* ct_state() - return the current context tracking state if known
*
* Returns the current cpu's context tracking state if context tracking
* is enabled. If context tracking is disabled, returns
* CONTEXT_DISABLED. This should be used primarily for debugging.
*/
static inline enum ctx_state ct_state(void)
{
return context_tracking_is_enabled() ?
this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
}
#else
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 enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
#endif /* !CONFIG_CONTEXT_TRACKING */
#define CT_WARN_ON(cond) WARN_ON(context_tracking_is_enabled() && (cond))
#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)
{
if (vtime_accounting_enabled())
vtime_guest_enter(current);
else
current->flags |= PF_VCPU;
if (context_tracking_is_enabled())
__context_tracking_enter(CONTEXT_GUEST);
}
static inline void guest_exit(void)
{
if (context_tracking_is_enabled())
__context_tracking_exit(CONTEXT_GUEST);
if (vtime_accounting_enabled())
vtime_guest_exit(current);
else
current->flags &= ~PF_VCPU;
}
#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