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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 /kernel/context_tracking.c
parentad65782fba507d91a0a98f519b59e79cac1b474c (diff)
downloadlinux-sh-48d6a816a8bf36e2a197c322697323003bdc1cfe.tar.gz
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 'kernel/context_tracking.c')
-rw-r--r--kernel/context_tracking.c23
1 files changed, 2 insertions, 21 deletions
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 6e89e094c80e..b6a186c4b886 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 @@ void context_tracking_user_exit(void)
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