context_tracking: Optimize guest APIs off case with static key
Optimize guest entry/exit APIs with static keys. This minimize
the overhead for those who enable CONFIG_NO_HZ_FULL without
always using it. Having no range passed to nohz_full= should
result in the probes overhead to be minimized.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 6e89e09..b6a186c 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -21,8 +21,10 @@
#include <linux/export.h>
struct static_key context_tracking_enabled = STATIC_KEY_INIT_FALSE;
+EXPORT_SYMBOL_GPL(context_tracking_enabled);
DEFINE_PER_CPU(struct context_tracking, context_tracking);
+EXPORT_SYMBOL_GPL(context_tracking);
void context_tracking_cpu_set(int cpu)
{
@@ -163,27 +165,6 @@
local_irq_restore(flags);
}
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-void guest_enter(void)
-{
- if (vtime_accounting_enabled())
- vtime_guest_enter(current);
- else
- current->flags |= PF_VCPU;
-}
-EXPORT_SYMBOL_GPL(guest_enter);
-
-void guest_exit(void)
-{
- if (vtime_accounting_enabled())
- vtime_guest_exit(current);
- else
- current->flags &= ~PF_VCPU;
-}
-EXPORT_SYMBOL_GPL(guest_exit);
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
-
-
/**
* context_tracking_task_switch - context switch the syscall callbacks
* @prev: the task that is being switched out
