From a1dabb6bfffccb897eff3e1d102dacf2a4bedf3b Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Tue, 21 Dec 2010 17:09:01 -0800 Subject: time: Add nsecs_to_cputime64 interface for asm-generic Add nsecs_to_cputime64 interface. This is used in following patches that updates cpu irq stat based on ns granularity info in IRQ_TIME_ACCOUNTING. Tested-by: Shaun Ruffell Signed-off-by: Venkatesh Pallipadi Signed-off-by: Peter Zijlstra LKML-Reference: <1292980144-28796-3-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar --- kernel/time.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'kernel/time.c') diff --git a/kernel/time.c b/kernel/time.c index 32174359576..55337a816b2 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -645,7 +645,7 @@ u64 nsec_to_clock_t(u64 x) } /** - * nsecs_to_jiffies - Convert nsecs in u64 to jiffies + * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 * * @n: nsecs in u64 * @@ -657,7 +657,7 @@ u64 nsec_to_clock_t(u64 x) * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years */ -unsigned long nsecs_to_jiffies(u64 n) +u64 nsecs_to_jiffies64(u64 n) { #if (NSEC_PER_SEC % HZ) == 0 /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ @@ -674,6 +674,25 @@ unsigned long nsecs_to_jiffies(u64 n) #endif } + +/** + * nsecs_to_jiffies - Convert nsecs in u64 to jiffies + * + * @n: nsecs in u64 + * + * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. + * And this doesn't return MAX_JIFFY_OFFSET since this function is designed + * for scheduler, not for use in device drivers to calculate timeout value. + * + * note: + * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) + * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years + */ +unsigned long nsecs_to_jiffies(u64 n) +{ + return (unsigned long)nsecs_to_jiffies64(n); +} + #if (BITS_PER_LONG < 64) u64 get_jiffies_64(void) { -- cgit v1.2.3