From 5787536edf18e33d06e2bf038bfd0910f4def213 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Fri, 8 Jan 2010 14:43:08 -0800 Subject: [PATCH] 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 Cc: Arjan van de Ven Cc: Len Brown Cc: Venkatesh Pallipadi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/cpuidle/governors/menu.c | 12 +++++++++--- 1 file 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 #include #include +#include #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 -- 2.30.2