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authorFrederic Weisbecker <fweisbec@gmail.com>2013-07-10 02:44:35 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2013-08-14 17:14:46 +0200
commit48d6a816a8bf36e2a197c322697323003bdc1cfe (patch)
tree6a51b602ec4451b8443b2b58337e9a55c84ceb48 /include/linux/context_tracking.h
parentad65782fba507d91a0a98f519b59e79cac1b474c (diff)
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>
Diffstat (limited to 'include/linux/context_tracking.h')
-rw-r--r--include/linux/context_tracking.h19
1 files changed, 17 insertions, 2 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 38ab60b3f3a6..8854eadb2142 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -95,8 +95,23 @@ static inline void context_tracking_init(void) { }
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-extern void guest_enter(void);
-extern void guest_exit(void);
+static inline void guest_enter(void)
+{
+ if (static_key_false(&context_tracking_enabled) &&
+ vtime_accounting_enabled())
+ vtime_guest_enter(current);
+ else
+ current->flags |= PF_VCPU;
+}
+
+static inline void guest_exit(void)
+{
+ if (static_key_false(&context_tracking_enabled) &&
+ vtime_accounting_enabled())
+ vtime_guest_exit(current);
+ else
+ current->flags &= ~PF_VCPU;
+}
#else
static inline void guest_enter(void)
{