diff options
| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2010-01-08 14:43:08 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-01-11 09:34:07 -0800 |
| commit | 5787536edf18e33d06e2bf038bfd0910f4def213 (patch) | |
| tree | 6d1874d02111cebc83fa1a6d1de3dedc0963ff53 /drivers/cpuidle/governors/menu.c | |
| parent | 006b4298f26984d514546fe4e53371761f66b643 (diff) | |
| download | lwn-5787536edf18e33d06e2bf038bfd0910f4def213.tar.gz lwn-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 'drivers/cpuidle/governors/menu.c')
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 12 |
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 |