The following commit has been merged into the sched/core branch of tip: Commit-ID: 023e9deb51c9e1aafacbd421e55beadcb8e87f53 Gitweb: https://git.kernel.org/tip/023e9deb51c9e1aafacbd421e55beadcb8e87f53 Author: Frederic Weisbecker <frederic@xxxxxxxxxx> AuthorDate: Wed, 16 Oct 2019 04:56:56 +02:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Tue, 29 Oct 2019 10:01:16 +01:00 context_tracking: Check static key on context_tracking_enabled_*cpu() guest_enter() doesn't call context_tracking_enabled() before calling context_tracking_enabled_this_cpu(). Therefore the guest code doesn't benefit from the static key on the fast path. Just make sure that context_tracking_enabled_*cpu() functions check the static key by themselves to propagate the optimization. Reported-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Rafael J . Wysocki <rjw@xxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx> Cc: Wanpeng Li <wanpengli@xxxxxxxxxxx> Cc: Yauheni Kaliuta <yauheni.kaliuta@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20191016025700.31277-11-frederic@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- include/linux/context_tracking_state.h | 4 ++-- include/linux/vtime.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h index 5877177..e7fe667 100644 --- a/include/linux/context_tracking_state.h +++ b/include/linux/context_tracking_state.h @@ -33,12 +33,12 @@ static inline bool context_tracking_enabled(void) static inline bool context_tracking_enabled_cpu(int cpu) { - return per_cpu(context_tracking.active, cpu); + return context_tracking_enabled() && per_cpu(context_tracking.active, cpu); } static inline bool context_tracking_enabled_this_cpu(void) { - return __this_cpu_read(context_tracking.active); + return context_tracking_enabled() && __this_cpu_read(context_tracking.active); } static inline bool context_tracking_in_user(void) diff --git a/include/linux/vtime.h b/include/linux/vtime.h index e2733bf..2cdeca0 100644 --- a/include/linux/vtime.h +++ b/include/linux/vtime.h @@ -33,12 +33,12 @@ static inline bool vtime_accounting_enabled(void) static inline bool vtime_accounting_enabled_cpu(int cpu) { - return (vtime_accounting_enabled() && context_tracking_enabled_cpu(cpu)); + return context_tracking_enabled_cpu(cpu); } static inline bool vtime_accounting_enabled_this_cpu(void) { - return (vtime_accounting_enabled() && context_tracking_enabled_this_cpu()); + return context_tracking_enabled_this_cpu(); } extern void vtime_task_switch_generic(struct task_struct *prev);