sched/cputime: Convert task/group cputime to nsecs

Now that most cputime readers use the transition API which return the
task cputime in old style cputime_t, we can safely store the cputime in
nsecs. This will eventually make cputime statistics less opaque and more
granular. Back and forth convertions between cputime_t and nsecs in order
to deal with cputime_t random granularity won't be needed anymore.

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/1485832191-26889-8-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 16 insertions, 9 deletions

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 68b915650cae..6d451936a858 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1411,6 +1411,8 @@ static void fill_note(struct memelfnote *note, const char *name, int type,
 static void fill_prstatus(struct elf_prstatus *prstatus,
 		struct task_struct *p, long signr)
 {
+	struct timeval tv;
+
 	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
 	prstatus->pr_sigpend = p->pending.signal.sig[0];
 	prstatus->pr_sighold = p->blocked.sig[0];
@@ -1437,8 +1439,13 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 		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);
+	tv = ns_to_timeval(p->signal->cutime);
+	prstatus->pr_cutime.tv_sec = tv.tv_sec;
+	prstatus->pr_cutime.tv_usec = tv.tv_usec;
+
+	tv = ns_to_timeval(p->signal->cstime);
+	prstatus->pr_cstime.tv_sec = tv.tv_sec;
+	prstatus->pr_cstime.tv_usec = tv.tv_usec;
 }
 
 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 6ccd9df7247a..e1f373460257 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1358,8 +1358,8 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 		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);
+	prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
+	prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
 
 	prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
 	prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 25b54cf0c042..fe12b519d09b 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -401,7 +401,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 	unsigned long long start_time;
 	unsigned long cmin_flt = 0, cmaj_flt = 0;
 	unsigned long  min_flt = 0,  maj_flt = 0;
-	cputime_t cutime, cstime, utime, stime;
+	u64 cutime, cstime, utime, stime;
 	u64 cgtime, gtime;
 	unsigned long rsslim = 0;
 	char tcomm[sizeof(task->comm)];
@@ -497,10 +497,10 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 	seq_put_decimal_ull(m, " ", cmin_flt);
 	seq_put_decimal_ull(m, " ", maj_flt);
 	seq_put_decimal_ull(m, " ", cmaj_flt);
-	seq_put_decimal_ull(m, " ", cputime_to_clock_t(utime));
-	seq_put_decimal_ull(m, " ", cputime_to_clock_t(stime));
-	seq_put_decimal_ll(m, " ", cputime_to_clock_t(cutime));
-	seq_put_decimal_ll(m, " ", cputime_to_clock_t(cstime));
+	seq_put_decimal_ull(m, " ", nsec_to_clock_t(utime));
+	seq_put_decimal_ull(m, " ", nsec_to_clock_t(stime));
+	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cutime));
+	seq_put_decimal_ll(m, " ", nsec_to_clock_t(cstime));
 	seq_put_decimal_ll(m, " ", priority);
 	seq_put_decimal_ll(m, " ", nice);
 	seq_put_decimal_ll(m, " ", num_threads);