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drivers/cpuidle/governors/menu.c: fix undefined reference to `__udivdi3'

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menu: use proper 64 bit math

The new menu governor is incorrectly doing a 64 bit divide.  Compile
tested only

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Stephen Hemminger
2010-01-08 14:43:08 -08:00
committed by Linus Torvalds
parent 006b4298f2
commit 5787536edf
1 changed files with 9 additions and 3 deletions
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12
drivers/cpuidle/governors/menu.c
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@@ -18,6 +18,7 @@
#include <linux/hrtimer.h> #include <linux/hrtimer.h>
#include <linux/tick.h> #include <linux/tick.h>
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/math64.h>
#define BUCKETS 12 #define BUCKETS 12
#define RESOLUTION 1024 #define RESOLUTION 1024
@@ -169,6 +170,12 @@ static DEFINE_PER_CPU(struct menu_device, menu_devices);
static void menu_update(struct cpuidle_device *dev); static void menu_update(struct cpuidle_device *dev);
/* This implements DIV_ROUND_CLOSEST but avoids 64 bit division */
static u64 div_round64(u64 dividend, u32 divisor)
{
return div_u64(dividend + (divisor / 2), divisor);
}
/** /**
* menu_select - selects the next idle state to enter * menu_select - selects the next idle state to enter
* @dev: the CPU * @dev: the CPU
@@ -209,9 +216,8 @@ static int menu_select(struct cpuidle_device *dev)
data->correction_factor[data->bucket] = RESOLUTION * DECAY; data->correction_factor[data->bucket] = RESOLUTION * DECAY;
/* Make sure to round up for half microseconds */ /* Make sure to round up for half microseconds */
data->predicted_us = DIV_ROUND_CLOSEST( data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket],
data->expected_us * data->correction_factor[data->bucket], RESOLUTION * DECAY);
RESOLUTION * DECAY);
/* /*
* We want to default to C1 (hlt), not to busy polling * We want to default to C1 (hlt), not to busy polling