From e53051e757d6cd66741955b93581e54415e48a70 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 1 Mar 2017 09:21:10 +0100 Subject: s390/cputime: provide archicture specific cputime_to_nsecs The generic cputime_to_nsecs function first converts the cputime to micro-seconds and then multiplies the result with 1000. This looses some bits of accuracy, provide our own version of cputime_to_nsecs that does not loose precision. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/cputime.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h index e5672d6276a6..9072bf63a846 100644 --- a/arch/s390/include/asm/cputime.h +++ b/arch/s390/include/asm/cputime.h @@ -8,6 +8,7 @@ #define _S390_CPUTIME_H #include +#include #define CPUTIME_PER_USEC 4096ULL #define CPUTIME_PER_SEC (CPUTIME_PER_USEC * USEC_PER_SEC) @@ -17,13 +18,18 @@ #define cmpxchg_cputime(ptr, old, new) cmpxchg64(ptr, old, new) /* - * Convert cputime to microseconds and back. + * Convert cputime to microseconds. */ static inline u64 cputime_to_usecs(const u64 cputime) { return cputime >> 12; } +/* + * Convert cputime to nanoseconds. + */ +#define cputime_to_nsecs(cputime) tod_to_ns(cputime) + u64 arch_cpu_idle_time(int cpu); #define arch_idle_time(cpu) arch_cpu_idle_time(cpu) -- cgit v1.2.3