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authorRik van Riel <riel@redhat.com>2015-02-10 15:27:52 -0500
committerFrederic Weisbecker <fweisbec@gmail.com>2015-03-09 15:42:57 +0100
commit19fdd98b6253404c6bdd6927bde9f962729376f7 (patch)
tree7e9f28b0b06ce051274bf0b9e23c4c6d52842828 /kernel/context_tracking.c
parenta3a9c7dff25791f3a1041aa96e770af662d99a35 (diff)
downloadlinux-sh-19fdd98b6253404c6bdd6927bde9f962729376f7.tar.gz
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@linux.vnet.ibm.com> Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will deacon <will.deacon@arm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'kernel/context_tracking.c')
-rw-r--r--kernel/context_tracking.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 17715d811b71..a2c0866384e8 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);
}