This is a note to let you know that I've just added the patch titled
powerpc: Fix wrong divisor in usecs_to_cputime
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-fix-wrong-divisor-in-usecs_to_cputime.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 9f5072d4f63f28d30d343573830ac6c85fc0deff Mon Sep 17 00:00:00 2001
From: Andreas Schwab <[email protected]>
Date: Fri, 9 Dec 2011 11:35:08 +0000
Subject: powerpc: Fix wrong divisor in usecs_to_cputime
From: Andreas Schwab <[email protected]>
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 <[email protected]>
Acked-by: Anton Blanchard <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/powerpc/include/asm/cputime.h | 6 +++---
arch/powerpc/kernel/time.c | 10 +++++-----
2 files changed, 8 insertions(+), 8 deletions(-)
--- a/arch/powerpc/include/asm/cputime.h
+++ b/arch/powerpc/include/asm/cputime.h
@@ -126,11 +126,11 @@ static inline u64 cputime64_to_jiffies64
/*
* 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
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;
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -168,13 +168,13 @@ 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;
@@ -192,8 +192,8 @@ 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);
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/powerpc-fix-wrong-divisor-in-usecs_to_cputime.patch
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