sched/cputime: Convert guest time accounting to nsecs (u64)

cputime_t is being obsolete and replaced by nsecs units in order to make
internal timestamps less opaque and more granular.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-6-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/cputime.c

@@ -158,7 +158,7 @@ void account_guest_time(struct task_struct *p, cputime_t cputime)
 	/* Add guest time to process. */
 	p->utime += cputime;
 	account_group_user_time(p, cputime);
-	p->gtime += cputime;
+	p->gtime += cputime_to_nsecs(cputime);
 
 	/* Add guest time to cpustat. */
 	if (task_nice(p) > 0) {
@@ -824,10 +824,10 @@ void vtime_init_idle(struct task_struct *t, int cpu)
 	local_irq_restore(flags);
 }
 
-cputime_t task_gtime(struct task_struct *t)
+u64 task_gtime(struct task_struct *t)
 {
 	unsigned int seq;
-	cputime_t gtime;
+	u64 gtime;
 
 	if (!vtime_accounting_enabled())
 		return t->gtime;
@@ -837,7 +837,7 @@ cputime_t task_gtime(struct task_struct *t)
 
 		gtime = t->gtime;
 		if (t->vtime_snap_whence == VTIME_SYS && t->flags & PF_VCPU)
-			gtime += vtime_delta(t);
+			gtime += cputime_to_nsecs(vtime_delta(t));
 
 	} while (read_seqcount_retry(&t->vtime_seqcount, seq));