timers/posix-timers: Convert internals to use nsecs

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

Also convert posix-cpu-timers to use nsec based internal counters to
simplify it.
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/1485832191-26889-19-git-send-email-fweisbec@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/posix-timers.h

@@ -8,19 +8,9 @@
 #include <linux/alarmtimer.h>
 
 
-static inline unsigned long long cputime_to_expires(cputime_t expires)
-{
-	return (__force unsigned long long)expires;
-}
-
-static inline cputime_t expires_to_cputime(unsigned long long expires)
-{
-	return (__force cputime_t)expires;
-}
-
 struct cpu_timer_list {
 	struct list_head entry;
-	unsigned long long expires, incr;
+	u64 expires, incr;
 	struct task_struct *task;
 	int firing;
 };

include/linux/sched.h

@@ -755,7 +755,7 @@ struct signal_struct {
 	struct thread_group_cputimer cputimer;
 
 	/* Earliest-expiration cache. */
-	struct task_cputime_t cputime_expires;
+	struct task_cputime cputime_expires;
 
 #ifdef CONFIG_NO_HZ_FULL
 	atomic_t tick_dep_mask;
@@ -1689,7 +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_t cputime_expires;
+	struct task_cputime cputime_expires;
 	struct list_head cpu_timers[3];
 
 /* process credentials */
@@ -3527,7 +3527,7 @@ 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_t *times);
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
 
 static inline void thread_group_cputime_t(struct task_struct *tsk,
 					  struct task_cputime_t *cputime)

kernel/fork.c

@@ -1313,7 +1313,7 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
 
 	cpu_limit = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
 	if (cpu_limit != RLIM_INFINITY) {
-		sig->cputime_expires.prof_exp = secs_to_cputime(cpu_limit);
+		sig->cputime_expires.prof_exp = cpu_limit * NSEC_PER_SEC;
 		sig->cputimer.running = true;
 	}
 

kernel/sched/cputime.c

@@ -122,7 +122,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime)
 
 	/* Add user time to process. */
 	p->utime += cputime_to_nsecs(cputime);
-	account_group_user_time(p, cputime);
+	account_group_user_time(p, cputime_to_nsecs(cputime));
 
 	index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
 
@@ -144,7 +144,7 @@ void account_guest_time(struct task_struct *p, cputime_t cputime)
 
 	/* Add guest time to process. */
 	p->utime += cputime_to_nsecs(cputime);
-	account_group_user_time(p, cputime);
+	account_group_user_time(p, cputime_to_nsecs(cputime));
 	p->gtime += cputime_to_nsecs(cputime);
 
 	/* Add guest time to cpustat. */
@@ -168,7 +168,7 @@ void account_system_index_time(struct task_struct *p,
 {
 	/* Add system time to process. */
 	p->stime += cputime_to_nsecs(cputime);
-	account_group_system_time(p, cputime);
+	account_group_system_time(p, cputime_to_nsecs(cputime));
 
 	/* Add system time to cpustat. */
 	task_group_account_field(p, index, cputime_to_nsecs(cputime));

kernel/sched/stats.h

@@ -216,7 +216,7 @@ static inline bool cputimer_running(struct task_struct *tsk)
  * running CPU and update the utime field there.
  */
 static inline void account_group_user_time(struct task_struct *tsk,
-					   cputime_t cputime)
+					   u64 cputime)
 {
 	struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
 
@@ -237,7 +237,7 @@ static inline void account_group_user_time(struct task_struct *tsk,
  * running CPU and update the stime field there.
  */
 static inline void account_group_system_time(struct task_struct *tsk,
-					     cputime_t cputime)
+					     u64 cputime)
 {
 	struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
 

kernel/time/itimer.c

@@ -53,15 +53,15 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 	cval = it->expires;
 	cinterval = it->incr;
 	if (cval) {
-		struct task_cputime_t cputime;
+		struct task_cputime cputime;
 		cputime_t t;
 
 		thread_group_cputimer(tsk, &cputime);
 		if (clock_id == CPUCLOCK_PROF)
-			t = cputime.utime + cputime.stime;
+			t = nsecs_to_cputime(cputime.utime + cputime.stime);
 		else
 			/* CPUCLOCK_VIRT */
-			t = cputime.utime;
+			t = nsecs_to_cputime(cputime.utime);
 
 		if (cval < t)
 			/* about to fire */