vtime: Optimize full dynticks accounting off case with static keys

If no CPU is in the full dynticks range, we can avoid the full
dynticks cputime accounting through generic vtime along with its
overhead and use the traditional tick based accounting instead.

Let's do this and nope the off case with static keys.

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>

1 files changed, 2 insertions, 4 deletions

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 82ec4870e064..158158704c30 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -74,8 +74,7 @@ static inline void context_tracking_init(void) { }
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 static inline void guest_enter(void)
 {
-        if (static_key_false(&context_tracking_enabled) &&
-            vtime_accounting_enabled())
+        if (vtime_accounting_enabled())
                 vtime_guest_enter(current);
         else
                 current->flags |= PF_VCPU;
@@ -83,8 +82,7 @@ static inline void guest_enter(void)
 
 static inline void guest_exit(void)
 {
-        if (static_key_false(&context_tracking_enabled) &&
-            vtime_accounting_enabled())
+        if (vtime_accounting_enabled())
                 vtime_guest_exit(current);
         else
                 current->flags &= ~PF_VCPU;