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>

1 files changed, 29 insertions, 3 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 252ff25983c8..9cc722f77799 100644
--- a/include/linux/sched.h
+++ b/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.