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authorFrederic Weisbecker <fweisbec@gmail.com>2013-07-11 20:27:43 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2013-08-14 17:14:48 +0200
commit1b6a259aa5ab16d8b215bfc19ff7c9ffa8858f10 (patch)
tree13aad3cfda4ff9c11e8e528685be39292c20c91d /kernel/context_tracking.c
parentcontext_tracking: Optimize context switch off case with static keys (diff)
downloadlinux-1b6a259aa5ab16d8b215bfc19ff7c9ffa8858f10.tar.xz
linux-1b6a259aa5ab16d8b215bfc19ff7c9ffa8858f10.zip
context_tracking: User/kernel broundary cross trace events
This can be useful to track all kernel/user round trips. And it's also helpful to debug the context tracking subsystem. 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.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index c17822673c39..247091bf0587 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -20,6 +20,9 @@
#include <linux/hardirq.h>
#include <linux/export.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/context_tracking.h>
+
struct static_key context_tracking_enabled = STATIC_KEY_INIT_FALSE;
EXPORT_SYMBOL_GPL(context_tracking_enabled);
@@ -64,6 +67,7 @@ void context_tracking_user_enter(void)
local_irq_save(flags);
if ( __this_cpu_read(context_tracking.state) != IN_USER) {
if (__this_cpu_read(context_tracking.active)) {
+ trace_user_enter(0);
/*
* At this stage, only low level arch entry code remains and
* then we'll run in userspace. We can assume there won't be
@@ -159,6 +163,7 @@ void context_tracking_user_exit(void)
*/
rcu_user_exit();
vtime_user_exit(current);
+ trace_user_exit(0);
}
__this_cpu_write(context_tracking.state, IN_KERNEL);
}