linux-kernel - [PATCH 09/14] sched/vtime: Introduce vtime_accounting_enabled

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Date:   Wed, 16 Oct 2019 04:56:55 +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 09/14] sched/vtime: Introduce vtime_accounting_enabled_cpu()

This allows us to check if a remote CPU runs vtime accounting
(ie: is nohz_full). We'll need that to reliably support reading kcpustat
on nohz_full CPUs.

Also simplify a bit the condition in the local flavoured function while
at it.

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/vtime.h | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index eb2e7a19054b..e2733bf33541 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -31,14 +31,14 @@ static inline bool vtime_accounting_enabled(void)
 	return context_tracking_enabled();
 }
 
+static inline bool vtime_accounting_enabled_cpu(int cpu)
+{
+	return (vtime_accounting_enabled() && context_tracking_enabled_cpu(cpu));
+}
+
 static inline bool vtime_accounting_enabled_this_cpu(void)
 {
-	if (vtime_accounting_enabled()) {
-		if (context_tracking_enabled_this_cpu())
-			return true;
-	}
-
-	return false;
+	return (vtime_accounting_enabled() && context_tracking_enabled_this_cpu());
 }
 
 extern void vtime_task_switch_generic(struct task_struct *prev);
@@ -51,6 +51,7 @@ static inline void vtime_task_switch(struct task_struct *prev)
 
 #else /* !CONFIG_VIRT_CPU_ACCOUNTING */
 
+static inline bool vtime_accounting_enabled_cpu(int cpu) {return false; }
 static inline bool vtime_accounting_enabled_this_cpu(void) { return false; }
 static inline void vtime_task_switch(struct task_struct *prev) { }
 
-- 
2.23.0