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Message-Id: <20191016025700.31277-11-frederic@kernel.org>
Date: Wed, 16 Oct 2019 04:56:56 +0200
From: Frederic Weisbecker <frederic@...nel.org>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Frederic Weisbecker <frederic@...nel.org>,
Jacek Anaszewski <jacek.anaszewski@...il.com>,
Peter Zijlstra <peterz@...radead.org>,
Wanpeng Li <wanpengli@...cent.com>,
"Rafael J . Wysocki" <rjw@...ysocki.net>,
Rik van Riel <riel@...riel.com>,
Thomas Gleixner <tglx@...utronix.de>,
Yauheni Kaliuta <yauheni.kaliuta@...hat.com>,
Ingo Molnar <mingo@...nel.org>,
Viresh Kumar <viresh.kumar@...aro.org>,
Pavel Machek <pavel@....cz>
Subject: [PATCH 10/14] 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@...radead.org>
Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
Cc: Yauheni Kaliuta <yauheni.kaliuta@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Rik van Riel <riel@...riel.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Wanpeng Li <wanpengli@...cent.com>
Cc: Ingo Molnar <mingo@...nel.org>
---
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 587717705727..e7fe6678b7ad 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 e2733bf33541..2cdeca062db3 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);
--
2.23.0
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