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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2013-07-10 02:44:35 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2013-08-14 17:14:46 +0200 |
| commit | 48d6a816a8bf36e2a197c322697323003bdc1cfe (patch) | |
| tree | 6a51b602ec4451b8443b2b58337e9a55c84ceb48 /kernel/context_tracking.c | |
| parent | ad65782fba507d91a0a98f519b59e79cac1b474c (diff) | |
| download | linux-48d6a816a8bf36e2a197c322697323003bdc1cfe.tar.gz linux-48d6a816a8bf36e2a197c322697323003bdc1cfe.tar.bz2 linux-48d6a816a8bf36e2a197c322697323003bdc1cfe.zip | |
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.c | 23 |
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 |