procfs: do not confuse jiffies with cputime64_t

Commit 2a95ea6c0d129b4 ("procfs: do not overflow get_{idle,iowait}_time
for nohz") did not take into account that one some architectures jiffies
and cputime use different units.

This causes get_idle_time() to return numbers in the wrong units, making
the idle time fields in /proc/stat wrong.

Instead of converting the usec value returned by
get_cpu_{idle,iowait}_time_us to units of jiffies, use the new function
usecs_to_cputime64 to convert it to the correct unit of cputime64_t.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Artem S. Tashkinov" <t.artem@mailcity.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 5 insertions, 0 deletions

diff --git a/arch/ia64/include/asm/cputime.h b/arch/ia64/include/asm/cputime.h
index 6073b187528a..5a274af31b2b 100644
--- a/arch/ia64/include/asm/cputime.h
+++ b/arch/ia64/include/asm/cputime.h
@@ -60,6 +60,7 @@ typedef u64 cputime64_t;
  */
 #define cputime_to_usecs(__ct)          ((__ct) / NSEC_PER_USEC)
 #define usecs_to_cputime(__usecs)       ((__usecs) * NSEC_PER_USEC)
+#define usecs_to_cputime64(__usecs)     usecs_to_cputime(__usecs)
 
 /*
  * Convert cputime <-> seconds
diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h
index 1cf20bdfbeca..98b7c4b49c9d 100644
--- a/arch/powerpc/include/asm/cputime.h
+++ b/arch/powerpc/include/asm/cputime.h
@@ -150,6 +150,8 @@ static inline cputime_t usecs_to_cputime(const unsigned long us)
         return ct;
 }
 
+#define usecs_to_cputime64(us)          usecs_to_cputime(us)
+
 /*
  * Convert cputime <-> seconds
  */
diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h
index 081434878296..b9acaaa175d8 100644
--- a/arch/s390/include/asm/cputime.h
+++ b/arch/s390/include/asm/cputime.h
@@ -87,6 +87,8 @@ usecs_to_cputime(const unsigned int m)
         return (cputime_t) m * 4096;
 }
 
+#define usecs_to_cputime64(m)           usecs_to_cputime(m)
+
 /*
  * Convert cputime to milliseconds and back.
  */