acct: Convert obsolete cputime type to nsecs

Use the new nsec based cputime accessors as part of the whole cputime
conversion from cputime_t to nsecs.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-13-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/sched.h

@@ -563,7 +563,7 @@ struct pacct_struct {
 	int			ac_flag;
 	long			ac_exitcode;
 	unsigned long		ac_mem;
-	cputime_t		ac_utime, ac_stime;
+	u64			ac_utime, ac_stime;
 	unsigned long		ac_minflt, ac_majflt;
 };
 

kernel/acct.c

@@ -453,8 +453,8 @@ static void fill_ac(acct_t *ac)
 	spin_lock_irq(&current->sighand->siglock);
 	tty = current->signal->tty;	/* Safe as we hold the siglock */
 	ac->ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
-	ac->ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
-	ac->ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
+	ac->ac_utime = encode_comp_t(nsec_to_AHZ(pacct->ac_utime));
+	ac->ac_stime = encode_comp_t(nsec_to_AHZ(pacct->ac_stime));
 	ac->ac_flag = pacct->ac_flag;
 	ac->ac_mem = encode_comp_t(pacct->ac_mem);
 	ac->ac_minflt = encode_comp_t(pacct->ac_minflt);
@@ -530,7 +530,7 @@ out:
 void acct_collect(long exitcode, int group_dead)
 {
 	struct pacct_struct *pacct = &current->signal->pacct;
-	cputime_t utime, stime;
+	u64 utime, stime;
 	unsigned long vsize = 0;
 
 	if (group_dead && current->mm) {
@@ -559,7 +559,8 @@ void acct_collect(long exitcode, int group_dead)
 		pacct->ac_flag |= ACORE;
 	if (current->flags & PF_SIGNALED)
 		pacct->ac_flag |= AXSIG;
-	task_cputime_t(current, &utime, &stime);
+
+	task_cputime(current, &utime, &stime);
 	pacct->ac_utime += utime;
 	pacct->ac_stime += stime;
 	pacct->ac_minflt += current->min_flt;