sched/cputime: Introduce special task_cputime_t() API to return old-typed cputime

This API returns a task's cputime in cputime_t in order to ease the
conversion of cputime internals to use nsecs units instead. Blindly
converting all cputime readers to use this API now will later let us
convert more smoothly and step by step all these places to use the
new nsec based cputime.

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/1485832191-26889-7-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/alpha/kernel/osf_sys.c

@@ -1154,7 +1154,7 @@ SYSCALL_DEFINE2(osf_getrusage, int, who, struct rusage32 __user *, ru)
 	memset(&r, 0, sizeof(r));
 	switch (who) {
 	case RUSAGE_SELF:
-		task_cputime(current, &utime, &stime);
+		task_cputime_t(current, &utime, &stime);
 		utime_jiffies = cputime_to_jiffies(utime);
 		stime_jiffies = cputime_to_jiffies(stime);
 		jiffies_to_timeval32(utime_jiffies, &r.ru_utime);

arch/x86/kernel/apm_32.c

@@ -913,7 +913,7 @@ static int apm_cpu_idle(struct cpuidle_device *dev,
 	unsigned int bucket;
 
 recalc:
-	task_cputime(current, &utime, &stime);
+	task_cputime_t(current, &utime, &stime);
 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 		use_apm_idle = 0;
 	} else if (jiffies_since_last_check > idle_period) {

drivers/isdn/mISDN/stack.c

@@ -306,7 +306,7 @@ mISDNStackd(void *data)
 	       "msg %d sleep %d stopped\n",
 	       dev_name(&st->dev->dev), st->msg_cnt, st->sleep_cnt,
 	       st->stopped_cnt);
-	task_cputime(st->thread, &utime, &stime);
+	task_cputime_t(st->thread, &utime, &stime);
 	printk(KERN_DEBUG
 	       "mISDNStackd daemon for %s utime(%ld) stime(%ld)\n",
 	       dev_name(&st->dev->dev), utime, stime);

fs/binfmt_elf.c

@@ -1421,19 +1421,19 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 	prstatus->pr_pgrp = task_pgrp_vnr(p);
 	prstatus->pr_sid = task_session_vnr(p);
 	if (thread_group_leader(p)) {
-		struct task_cputime cputime;
+		struct task_cputime_t cputime;
 
 		/*
 		 * This is the record for the group leader.  It shows the
 		 * group-wide total, not its individual thread total.
 		 */
-		thread_group_cputime(p, &cputime);
+		thread_group_cputime_t(p, &cputime);
 		cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
 		cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
 	} else {
 		cputime_t utime, stime;
 
-		task_cputime(p, &utime, &stime);
+		task_cputime_t(p, &utime, &stime);
 		cputime_to_timeval(utime, &prstatus->pr_utime);
 		cputime_to_timeval(stime, &prstatus->pr_stime);
 	}

fs/binfmt_elf_fdpic.c

@@ -1342,19 +1342,19 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 	prstatus->pr_pgrp = task_pgrp_vnr(p);
 	prstatus->pr_sid = task_session_vnr(p);
 	if (thread_group_leader(p)) {
-		struct task_cputime cputime;
+		struct task_cputime_t cputime;
 
 		/*
 		 * This is the record for the group leader.  It shows the
 		 * group-wide total, not its individual thread total.
 		 */
-		thread_group_cputime(p, &cputime);
+		thread_group_cputime_t(p, &cputime);
 		cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
 		cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
 	} else {
 		cputime_t utime, stime;
 
-		task_cputime(p, &utime, &stime);
+		task_cputime_t(p, &utime, &stime);
 		cputime_to_timeval(utime, &prstatus->pr_utime);
 		cputime_to_timeval(stime, &prstatus->pr_stime);
 	}

include/linux/sched.h

@@ -615,6 +615,13 @@ struct task_cputime {
 	unsigned long long sum_exec_runtime;
 };
 
+/* Temporary type to ease cputime_t to nsecs conversion */
+struct task_cputime_t {
+	cputime_t utime;
+	cputime_t stime;
+	unsigned long long sum_exec_runtime;
+};
+
 /* Alternate field names when used to cache expirations. */
 #define virt_exp	utime
 #define prof_exp	stime
@@ -748,7 +755,7 @@ struct signal_struct {
 	struct thread_group_cputimer cputimer;
 
 	/* Earliest-expiration cache. */
-	struct task_cputime cputime_expires;
+	struct task_cputime_t cputime_expires;
 
 #ifdef CONFIG_NO_HZ_FULL
 	atomic_t tick_dep_mask;
@@ -1682,7 +1689,7 @@ struct task_struct {
 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
 	unsigned long min_flt, maj_flt;
 
-	struct task_cputime cputime_expires;
+	struct task_cputime_t cputime_expires;
 	struct list_head cpu_timers[3];
 
 /* process credentials */
@@ -2286,6 +2293,19 @@ static inline void task_cputime_scaled(struct task_struct *t,
 }
 #endif
 
+static inline void task_cputime_t(struct task_struct *t,
+				  cputime_t *utime, cputime_t *stime)
+{
+	task_cputime(t, utime, stime);
+}
+
+static inline void task_cputime_t_scaled(struct task_struct *t,
+					 cputime_t *utimescaled,
+					 cputime_t *stimescaled)
+{
+	task_cputime_scaled(t, utimescaled, stimescaled);
+}
+
 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
 
@@ -3499,7 +3519,13 @@ static __always_inline bool need_resched(void)
  * Thread group CPU time accounting.
  */
 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
-void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime_t *times);
+
+static inline void thread_group_cputime_t(struct task_struct *tsk,
+					  struct task_cputime_t *times)
+{
+	thread_group_cputime(tsk, (struct task_cputime *)times);
+}
 
 /*
  * Reevaluate whether the task has signals pending delivery.

kernel/acct.c

@@ -559,7 +559,7 @@ void acct_collect(long exitcode, int group_dead)
 		pacct->ac_flag |= ACORE;
 	if (current->flags & PF_SIGNALED)
 		pacct->ac_flag |= AXSIG;
-	task_cputime(current, &utime, &stime);
+	task_cputime_t(current, &utime, &stime);
 	pacct->ac_utime += utime;
 	pacct->ac_stime += stime;
 	pacct->ac_minflt += current->min_flt;

kernel/delayacct.c

@@ -87,12 +87,12 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
 	unsigned long flags, t1;
 	s64 tmp;
 
-	task_cputime(tsk, &utime, &stime);
+	task_cputime_t(tsk, &utime, &stime);
 	tmp = (s64)d->cpu_run_real_total;
 	tmp += cputime_to_nsecs(utime + stime);
 	d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
 
-	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
+	task_cputime_t_scaled(tsk, &utimescaled, &stimescaled);
 	tmp = (s64)d->cpu_scaled_run_real_total;
 	tmp += cputime_to_nsecs(utimescaled + stimescaled);
 	d->cpu_scaled_run_real_total =

kernel/signal.c

@@ -1619,7 +1619,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
 				       task_uid(tsk));
 	rcu_read_unlock();
 
-	task_cputime(tsk, &utime, &stime);
+	task_cputime_t(tsk, &utime, &stime);
 	info.si_utime = cputime_to_clock_t(utime + tsk->signal->utime);
 	info.si_stime = cputime_to_clock_t(stime + tsk->signal->stime);
 
@@ -1704,7 +1704,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
 	info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));
 	rcu_read_unlock();
 
-	task_cputime(tsk, &utime, &stime);
+	task_cputime_t(tsk, &utime, &stime);
 	info.si_utime = cputime_to_clock_t(utime);
 	info.si_stime = cputime_to_clock_t(stime);
 

kernel/time/itimer.c

@@ -53,7 +53,7 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 	cval = it->expires;
 	cinterval = it->incr;
 	if (cval) {
-		struct task_cputime cputime;
+		struct task_cputime_t cputime;
 		cputime_t t;
 
 		thread_group_cputimer(tsk, &cputime);

kernel/time/posix-cpu-timers.c

@@ -115,7 +115,7 @@ static void bump_cpu_timer(struct k_itimer *timer,
  * Checks @cputime to see if all fields are zero.  Returns true if all fields
  * are zero, false if any field is nonzero.
  */
-static inline int task_cputime_zero(const struct task_cputime *cputime)
+static inline int task_cputime_zero(const struct task_cputime_t *cputime)
 {
 	if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
 		return 1;
@@ -126,7 +126,7 @@ static inline unsigned long long prof_ticks(struct task_struct *p)
 {
 	cputime_t utime, stime;
 
-	task_cputime(p, &utime, &stime);
+	task_cputime_t(p, &utime, &stime);
 
 	return cputime_to_expires(utime + stime);
 }
@@ -134,7 +134,7 @@ static inline unsigned long long virt_ticks(struct task_struct *p)
 {
 	cputime_t utime, stime;
 
-	task_cputime(p, &utime, &stime);
+	task_cputime_t(p, &utime, &stime);
 
 	return cputime_to_expires(utime);
 }
@@ -210,7 +210,7 @@ retry:
 	}
 }
 
-static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum)
+static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime_t *sum)
 {
 	__update_gt_cputime(&cputime_atomic->utime, sum->utime);
 	__update_gt_cputime(&cputime_atomic->stime, sum->stime);
@@ -218,7 +218,7 @@ static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct
 }
 
 /* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */
-static inline void sample_cputime_atomic(struct task_cputime *times,
+static inline void sample_cputime_atomic(struct task_cputime_t *times,
 					 struct task_cputime_atomic *atomic_times)
 {
 	times->utime = atomic64_read(&atomic_times->utime);
@@ -226,10 +226,10 @@ static inline void sample_cputime_atomic(struct task_cputime *times,
 	times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime);
 }
 
-void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime_t *times)
 {
 	struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
-	struct task_cputime sum;
+	struct task_cputime_t sum;
 
 	/* Check if cputimer isn't running. This is accessed without locking. */
 	if (!READ_ONCE(cputimer->running)) {
@@ -238,7 +238,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
 		 * values through the TIMER_ABSTIME flag, therefore we have
 		 * to synchronize the timer to the clock every time we start it.
 		 */
-		thread_group_cputime(tsk, &sum);
+		thread_group_cputime_t(tsk, &sum);
 		update_gt_cputime(&cputimer->cputime_atomic, &sum);
 
 		/*
@@ -262,21 +262,21 @@ static int cpu_clock_sample_group(const clockid_t which_clock,
 				  struct task_struct *p,
 				  unsigned long long *sample)
 {
-	struct task_cputime cputime;
+	struct task_cputime_t cputime;
 
 	switch (CPUCLOCK_WHICH(which_clock)) {
 	default:
 		return -EINVAL;
 	case CPUCLOCK_PROF:
-		thread_group_cputime(p, &cputime);
+		thread_group_cputime_t(p, &cputime);
 		*sample = cputime_to_expires(cputime.utime + cputime.stime);
 		break;
 	case CPUCLOCK_VIRT:
-		thread_group_cputime(p, &cputime);
+		thread_group_cputime_t(p, &cputime);
 		*sample = cputime_to_expires(cputime.utime);
 		break;
 	case CPUCLOCK_SCHED:
-		thread_group_cputime(p, &cputime);
+		thread_group_cputime_t(p, &cputime);
 		*sample = cputime.sum_exec_runtime;
 		break;
 	}
@@ -466,7 +466,7 @@ static void arm_timer(struct k_itimer *timer)
 {
 	struct task_struct *p = timer->it.cpu.task;
 	struct list_head *head, *listpos;
-	struct task_cputime *cputime_expires;
+	struct task_cputime_t *cputime_expires;
 	struct cpu_timer_list *const nt = &timer->it.cpu;
 	struct cpu_timer_list *next;
 
@@ -562,7 +562,7 @@ static int cpu_timer_sample_group(const clockid_t which_clock,
 				  struct task_struct *p,
 				  unsigned long long *sample)
 {
-	struct task_cputime cputime;
+	struct task_cputime_t cputime;
 
 	thread_group_cputimer(p, &cputime);
 	switch (CPUCLOCK_WHICH(which_clock)) {
@@ -761,7 +761,7 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
 		/*
 		 * Protect against sighand release/switch in exit/exec and
 		 * also make timer sampling safe if it ends up calling
-		 * thread_group_cputime().
+		 * thread_group_cputime_t().
 		 */
 		sighand = lock_task_sighand(p, &flags);
 		if (unlikely(sighand == NULL)) {
@@ -826,7 +826,7 @@ static void check_thread_timers(struct task_struct *tsk,
 {
 	struct list_head *timers = tsk->cpu_timers;
 	struct signal_struct *const sig = tsk->signal;
-	struct task_cputime *tsk_expires = &tsk->cputime_expires;
+	struct task_cputime_t *tsk_expires = &tsk->cputime_expires;
 	unsigned long long expires;
 	unsigned long soft;
 
@@ -934,7 +934,7 @@ static void check_process_timers(struct task_struct *tsk,
 	unsigned long long utime, ptime, virt_expires, prof_expires;
 	unsigned long long sum_sched_runtime, sched_expires;
 	struct list_head *timers = sig->cpu_timers;
-	struct task_cputime cputime;
+	struct task_cputime_t cputime;
 	unsigned long soft;
 
 	/*
@@ -1037,7 +1037,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
 	} else {
 		/*
 		 * Protect arm_timer() and timer sampling in case of call to
-		 * thread_group_cputime().
+		 * thread_group_cputime_t().
 		 */
 		sighand = lock_task_sighand(p, &flags);
 		if (unlikely(sighand == NULL)) {
@@ -1080,8 +1080,8 @@ out:
  * Returns true if any field of the former is greater than the corresponding
  * field of the latter if the latter field is set.  Otherwise returns false.
  */
-static inline int task_cputime_expired(const struct task_cputime *sample,
-					const struct task_cputime *expires)
+static inline int task_cputime_expired(const struct task_cputime_t *sample,
+					const struct task_cputime_t *expires)
 {
 	if (expires->utime && sample->utime >= expires->utime)
 		return 1;
@@ -1108,9 +1108,9 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
 	struct signal_struct *sig;
 
 	if (!task_cputime_zero(&tsk->cputime_expires)) {
-		struct task_cputime task_sample;
+		struct task_cputime_t task_sample;
 
-		task_cputime(tsk, &task_sample.utime, &task_sample.stime);
+		task_cputime_t(tsk, &task_sample.utime, &task_sample.stime);
 		task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime;
 		if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
 			return 1;
@@ -1133,7 +1133,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
 	 */
 	if (READ_ONCE(sig->cputimer.running) &&
 	    !READ_ONCE(sig->cputimer.checking_timer)) {
-		struct task_cputime group_sample;
+		struct task_cputime_t group_sample;
 
 		sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);
 

kernel/tsacct.c

@@ -66,11 +66,11 @@ void bacct_add_tsk(struct user_namespace *user_ns,
 		task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
 	rcu_read_unlock();
 
-	task_cputime(tsk, &utime, &stime);
+	task_cputime_t(tsk, &utime, &stime);
 	stats->ac_utime = cputime_to_usecs(utime);
 	stats->ac_stime = cputime_to_usecs(stime);
 
-	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
+	task_cputime_t_scaled(tsk, &utimescaled, &stimescaled);
 	stats->ac_utimescaled = cputime_to_usecs(utimescaled);
 	stats->ac_stimescaled = cputime_to_usecs(stimescaled);
 
@@ -159,7 +159,7 @@ void acct_update_integrals(struct task_struct *tsk)
 	unsigned long flags;
 
 	local_irq_save(flags);
-	task_cputime(tsk, &utime, &stime);
+	task_cputime_t(tsk, &utime, &stime);
 	__acct_update_integrals(tsk, utime, stime);
 	local_irq_restore(flags);
 }