cputime: Use accessors to read task cputime stats

This is in preparation for the full dynticks feature. While
remotely reading the cputime of a task running in a full
dynticks CPU, we'll need to do some extra-computation. This
way we can account the time it spent tickless in userspace
since its last cputime snapshot.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 13 insertions, 6 deletions

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 0c42cdbabecf..49d0b43458b7 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -33,6 +33,7 @@
 #include <linux/elf.h>
 #include <linux/utsname.h>
 #include <linux/coredump.h>
+#include <linux/sched.h>
 #include <asm/uaccess.h>
 #include <asm/param.h>
 #include <asm/page.h>
@@ -1320,8 +1321,11 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
         } else {
-                cputime_to_timeval(p->utime, &prstatus->pr_utime);
-                cputime_to_timeval(p->stime, &prstatus->pr_stime);
+                cputime_t utime, stime;
+
+                task_cputime(p, &utime, &stime);
+                cputime_to_timeval(utime, &prstatus->pr_utime);
+                cputime_to_timeval(stime, &prstatus->pr_stime);
         }
         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index dc84732e554f..cb240dd3b402 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1375,8 +1375,11 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
         } else {
-                cputime_to_timeval(p->utime, &prstatus->pr_utime);
-                cputime_to_timeval(p->stime, &prstatus->pr_stime);
+                cputime_t utime, stime;
+
+                task_cputime(p, &utime, &stime);
+                cputime_to_timeval(utime, &prstatus->pr_utime);
+                cputime_to_timeval(stime, &prstatus->pr_stime);
         }
         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 6a91e6ffbcbd..f7ed9ee46eb9 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -449,7 +449,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
                         do {
                                 min_flt += t->min_flt;
                                 maj_flt += t->maj_flt;
-                                gtime += t->gtime;
+                                gtime += task_gtime(t);
                                 t = next_thread(t);
                         } while (t != task);
 
@@ -472,7 +472,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
                 min_flt = task->min_flt;
                 maj_flt = task->maj_flt;
                 task_cputime_adjusted(task, &utime, &stime);
-                gtime = task->gtime;
+                gtime = task_gtime(task);
         }
 
         /* scale priority and nice values from timeslices to -20..20 */