[ 085/108] powerpc: Fix wrong divisor in usecs_to_cputime

Ben Hutchings
2012-07-23T01:42:49Z

From: Andreas Schwab <schwab@linux-m68k.org>

commit 9f5072d4f63f28d30d343573830ac6c85fc0deff upstream.

Commit d57af9b (taskstats: use real microsecond granularity for CPU times)
renamed msecs_to_cputime to usecs_to_cputime, but failed to update all
numbers on the way. This causes nonsensical cpu idle/iowait values to be
displayed in /proc/stat (the only user of usecs_to_cputime so far).

This also renames __cputime_msec_factor to __cputime_usec_factor, adapting
its value and using it directly in cputime_to_usecs instead of doing two
multiplications.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/powerpc/include/asm/cputime.h | 6 +++---
arch/powerpc/kernel/time.c | 10 +++++-----
2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h
index 1cf20bd..33a3580 100644
--- a/arch/powerpc/include/asm/cputime.h
+++ b/arch/powerpc/include/asm/cputime.h
@@ -126,11 +126,11 @@ static inline u64 cputime64_to_jiffies64(const cputime_t ct)
/*
* Convert cputime <-> microseconds
*/
-extern u64 __cputime_msec_factor;
+extern u64 __cputime_usec_factor;

static inline unsigned long cputime_to_usecs(const cputime_t ct)
{
- return mulhdu(ct, __cputime_msec_factor) * USEC_PER_MSEC;
+ return mulhdu(ct, __cputime_usec_factor);
}

static inline cputime_t usecs_to_cputime(const unsigned long us)
@@ -143,7 +143,7 @@ static inline cputime_t usecs_to_cputime(const unsigned long us)
sec = us / 1000000;
if (ct) {
ct *= tb_ticks_per_sec;
- do_div(ct, 1000);
+ do_div(ct, 1000000);
}
if (sec)
ct += (cputime_t) sec * tb_ticks_per_sec;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 9754743..567dd7c 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -158,13 +158,13 @@ EXPORT_SYMBOL_GPL(ppc_tb_freq);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
/*
* Factors for converting from cputime_t (timebase ticks) to
- * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds).
+ * jiffies, microseconds, seconds, and clock_t (1/USER_HZ seconds).
* These are all stored as 0.64 fixed-point binary fractions.
*/
u64 __cputime_jiffies_factor;
EXPORT_SYMBOL(__cputime_jiffies_factor);
-u64 __cputime_msec_factor;
-EXPORT_SYMBOL(__cputime_msec_factor);
+u64 __cputime_usec_factor;
+EXPORT_SYMBOL(__cputime_usec_factor);
u64 __cputime_sec_factor;
EXPORT_SYMBOL(__cputime_sec_factor);
u64 __cputime_clockt_factor;
@@ -182,8 +182,8 @@ static void calc_cputime_factors(void)

div128_by_32(HZ, 0, tb_ticks_per_sec, &res);
__cputime_jiffies_factor = res.result_low;
- div128_by_32(1000, 0, tb_ticks_per_sec, &res);
- __cputime_msec_factor = res.result_low;
+ div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
+ __cputime_usec_factor = res.result_low;
div128_by_32(1, 0, tb_ticks_per_sec, &res);
__cputime_sec_factor = res.result_low;
div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res);