[tip: sched/core] sched/vtime: Introduce vtime_accounting_enabled_cpu()

[tip-bot2 for Frederic Weisbecker]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     9adbb9dd4c4eb45e1129fc73d8de69ca72350f81
Gitweb:        https://git.kernel.org/tip/9adbb9dd4c4eb45e1129fc73d8de69ca72350f81
Author:        Frederic Weisbecker <frederic@xxxxxxxxxx>
AuthorDate:    Wed, 16 Oct 2019 04:56:55 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 29 Oct 2019 10:01:15 +01:00

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@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: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
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/20191016025700.31277-10-frederic@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 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 eb2e7a1..e2733bf 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_this_cpu(void)
+static inline bool vtime_accounting_enabled_cpu(int cpu)
 {
-	if (vtime_accounting_enabled()) {
-		if (context_tracking_enabled_this_cpu())
-			return true;
-	}
+	return (vtime_accounting_enabled() && context_tracking_enabled_cpu(cpu));
+}
 
-	return false;
+static inline bool vtime_accounting_enabled_this_cpu(void)
+{
+	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) { }