Commit-ID: 19fdd98b6253404c6bdd6927bde9f962729376f7
Gitweb: http://git.kernel.org/tip/19fdd98b6253404c6bdd6927bde9f962729376f7
Author: Rik van Riel <riel@xxxxxxxxxx>
AuthorDate: Tue, 10 Feb 2015 15:27:52 -0500
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Mon, 9 Mar 2015 15:42:57 +0100
context_tracking: Run vtime_user_enter/exit only when state == CONTEXT_USER
Only run vtime_user_enter, vtime_user_exit, and the user enter & exit
trace points when we are entering or exiting user state, respectively.
The KVM code in guest_enter and guest_exit already take care of calling
vtime_guest_enter and vtime_guest_exit, respectively.
The RCU code only distinguishes between "idle" and "not idle or kernel".
There should be no need to add an additional (unused) state there.
Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Will deacon <will.deacon@xxxxxxx>
Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: Luiz Capitulino <lcapitulino@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
kernel/context_tracking.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 17715d8..a2c0866 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -77,7 +77,6 @@ void context_tracking_enter(enum ctx_state state)
local_irq_save(flags);
if ( __this_cpu_read(context_tracking.state) != state) {
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
@@ -85,7 +84,10 @@ void context_tracking_enter(enum ctx_state state)
* user_exit() or rcu_irq_enter(). Let's remove RCU's dependency
* on the tick.
*/
- vtime_user_enter(current);
+ if (state == CONTEXT_USER) {
+ trace_user_enter(0);
+ vtime_user_enter(current);
+ }
rcu_user_enter();
}
/*
@@ -143,8 +145,10 @@ void context_tracking_exit(enum ctx_state state)
* RCU core about that (ie: we may need the tick again).
*/
rcu_user_exit();
- vtime_user_exit(current);
- trace_user_exit(0);
+ if (state == CONTEXT_USER) {
+ vtime_user_exit(current);
+ trace_user_exit(0);
+ }
}
__this_cpu_write(context_tracking.state, CONTEXT_KERNEL);
}
--
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