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| author | Rik van Riel <riel@redhat.com> | 2015-02-10 21:27:52 +0100 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2015-03-09 15:42:57 +0100 |
| commit | 19fdd98b6253404c6bdd6927bde9f962729376f7 (patch) | |
| tree | 7e9f28b0b06ce051274bf0b9e23c4c6d52842828 /kernel | |
| parent | context_tracking: Add stub context_tracking_is_enabled (diff) | |
| download | linux-19fdd98b6253404c6bdd6927bde9f962729376f7.tar.xz linux-19fdd98b6253404c6bdd6927bde9f962729376f7.zip | |
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')
| -rw-r--r-- | kernel/context_tracking.c | 12 |
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); } |