From 19fdd98b6253404c6bdd6927bde9f962729376f7 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Tue, 10 Feb 2015 15:27:52 -0500 Subject: [PATCH] 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 Signed-off-by: Rik van Riel Cc: Paul E. McKenney Cc: Andy Lutomirski Cc: Will deacon Cc: Marcelo Tosatti Cc: Christian Borntraeger Cc: Luiz Capitulino Cc: Paolo Bonzini Signed-off-by: Frederic Weisbecker --- 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); } -- 2.7.4