sched/irqtime: Remove needless IRQs disablement on kcpustat update

The callers of the functions performing irqtime kcpustat updates have
IRQS disabled, no need to disable them again.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1474849761-12678-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/cputime.c

@@ -78,30 +78,26 @@ EXPORT_SYMBOL_GPL(irqtime_account_irq);
 static cputime_t irqtime_account_hi_update(cputime_t maxtime)
 {
 	u64 *cpustat = kcpustat_this_cpu->cpustat;
-	unsigned long flags;
 	cputime_t irq_cputime;
 
-	local_irq_save(flags);
 	irq_cputime = nsecs_to_cputime64(__this_cpu_read(cpu_hardirq_time)) -
 		      cpustat[CPUTIME_IRQ];
 	irq_cputime = min(irq_cputime, maxtime);
 	cpustat[CPUTIME_IRQ] += irq_cputime;
-	local_irq_restore(flags);
+
 	return irq_cputime;
 }
 
 static cputime_t irqtime_account_si_update(cputime_t maxtime)
 {
 	u64 *cpustat = kcpustat_this_cpu->cpustat;
-	unsigned long flags;
 	cputime_t softirq_cputime;
 
-	local_irq_save(flags);
 	softirq_cputime = nsecs_to_cputime64(__this_cpu_read(cpu_softirq_time)) -
 			  cpustat[CPUTIME_SOFTIRQ];
 	softirq_cputime = min(softirq_cputime, maxtime);
 	cpustat[CPUTIME_SOFTIRQ] += softirq_cputime;
-	local_irq_restore(flags);
+
 	return softirq_cputime;
 }
 
@@ -295,6 +291,9 @@ static inline cputime_t account_other_time(cputime_t max)
 {
 	cputime_t accounted;
 
+	/* Shall be converted to a lockdep-enabled lightweight check */
+	WARN_ON_ONCE(!irqs_disabled());
+
 	accounted = steal_account_process_time(max);
 
 	if (accounted < max)