summaryrefslogtreecommitdiffstats
path: root/drivers/cpuidle/governors/menu.c
diff options
context:
space:
mode:
authorStephen Hemminger <shemminger@linux-foundation.org>2010-01-08 23:43:08 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2010-01-11 18:34:07 +0100
commit5787536edf18e33d06e2bf038bfd0910f4def213 (patch)
tree6d1874d02111cebc83fa1a6d1de3dedc0963ff53 /drivers/cpuidle/governors/menu.c
parentDocumentation: update ring-buffer-design.txt (diff)
downloadlinux-5787536edf18e33d06e2bf038bfd0910f4def213.tar.xz
linux-5787536edf18e33d06e2bf038bfd0910f4def213.zip
drivers/cpuidle/governors/menu.c: fix undefined reference to `__udivdi3'
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>
Diffstat (limited to '')
-rw-r--r--drivers/cpuidle/governors/menu.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 68104434ebb5..73655aeb3a60 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -18,6 +18,7 @@
#include <linux/hrtimer.h>
#include <linux/tick.h>
#include <linux/sched.h>
+#include <linux/math64.h>
#define BUCKETS 12
#define RESOLUTION 1024
@@ -169,6 +170,12 @@ static DEFINE_PER_CPU(struct menu_device, menu_devices);
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
* @dev: the CPU
@@ -209,9 +216,8 @@ static int menu_select(struct cpuidle_device *dev)
data->correction_factor[data->bucket] = RESOLUTION * DECAY;
/* Make sure to round up for half microseconds */
- data->predicted_us = DIV_ROUND_CLOSEST(
- data->expected_us * data->correction_factor[data->bucket],
- RESOLUTION * DECAY);
+ data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket],
+ RESOLUTION * DECAY);
/*
* We want to default to C1 (hlt), not to busy polling