timers/itimer: Convert internal cputime_t units to nsec

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

Also convert itimers to use nsec based internal counters. This simplifies
it and removes the whole game with error/inc_error which served to deal
with cputime_t random granularity.

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/1485832191-26889-20-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 16 insertions, 18 deletions

diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 890de52362d0..64aa189efe21 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -119,7 +119,7 @@ void run_posix_cpu_timers(struct task_struct *task);
 void posix_cpu_timers_exit(struct task_struct *task);
 void posix_cpu_timers_exit_group(struct task_struct *task);
 void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
-			   cputime_t *newval, cputime_t *oldval);
+			   u64 *newval, u64 *oldval);
 
 long clock_nanosleep_restart(struct restart_block *restart_block);
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index baa6a2834e0f..268fdd713089 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -568,10 +568,8 @@ struct pacct_struct {
 };
 
 struct cpu_itimer {
-	cputime_t expires;
-	cputime_t incr;
-	u32 error;
-	u32 incr_error;
+	u64 expires;
+	u64 incr;
 };
 
 /**
diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
index 1448637616d6..1bca99dbb98f 100644
--- a/include/trace/events/timer.h
+++ b/include/trace/events/timer.h
@@ -269,17 +269,17 @@ DEFINE_EVENT(hrtimer_class, hrtimer_cancel,
 TRACE_EVENT(itimer_state,
 
 	TP_PROTO(int which, const struct itimerval *const value,
-		 cputime_t expires),
+		 unsigned long long expires),
 
 	TP_ARGS(which, value, expires),
 
 	TP_STRUCT__entry(
-		__field(	int,		which		)
-		__field(	cputime_t,	expires		)
-		__field(	long,		value_sec	)
-		__field(	long,		value_usec	)
-		__field(	long,		interval_sec	)
-		__field(	long,		interval_usec	)
+		__field(	int,			which		)
+		__field(	unsigned long long,	expires		)
+		__field(	long,			value_sec	)
+		__field(	long,			value_usec	)
+		__field(	long,			interval_sec	)
+		__field(	long,			interval_usec	)
 	),
 
 	TP_fast_assign(
@@ -292,7 +292,7 @@ TRACE_EVENT(itimer_state,
 	),
 
 	TP_printk("which=%d expires=%llu it_value=%ld.%ld it_interval=%ld.%ld",
-		  __entry->which, (unsigned long long)__entry->expires,
+		  __entry->which, __entry->expires,
 		  __entry->value_sec, __entry->value_usec,
 		  __entry->interval_sec, __entry->interval_usec)
 );
@@ -305,14 +305,14 @@ TRACE_EVENT(itimer_state,
  */
 TRACE_EVENT(itimer_expire,
 
-	TP_PROTO(int which, struct pid *pid, cputime_t now),
+	TP_PROTO(int which, struct pid *pid, unsigned long long now),
 
 	TP_ARGS(which, pid, now),
 
 	TP_STRUCT__entry(
-		__field( int ,		which	)
-		__field( pid_t,		pid	)
-		__field( cputime_t,	now	)
+		__field( int ,			which	)
+		__field( pid_t,			pid	)
+		__field( unsigned long long,	now	)
 	),
 
 	TP_fast_assign(
@@ -322,7 +322,7 @@ TRACE_EVENT(itimer_expire,
 	),
 
 	TP_printk("which=%d pid=%d now=%llu", __entry->which,
-		  (int) __entry->pid, (unsigned long long)__entry->now)
+		  (int) __entry->pid, __entry->now)
 );
 
 #ifdef CONFIG_NO_HZ_COMMON