there is a similar helper in net/netfilter/nf_tables_api.c, this maybe become a common request someday. and avoid to call div_64 at some condition Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx> --- include/linux/jiffies.h | 1 + kernel/time/time.c | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index fa928242567d..1b6d31da7cbc 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -297,6 +297,7 @@ static inline u64 jiffies_to_nsecs(const unsigned long j) } extern u64 jiffies64_to_nsecs(u64 j); +extern u64 jiffies64_to_msecs(u64 j); extern unsigned long __msecs_to_jiffies(const unsigned int m); #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) diff --git a/kernel/time/time.c b/kernel/time/time.c index 2edb5088a70b..0083eb711fb7 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -719,6 +719,16 @@ u64 jiffies64_to_nsecs(u64 j) } EXPORT_SYMBOL(jiffies64_to_nsecs); +u64 jiffies64_to_msecs(const u64 j) +{ +#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) + return (MSEC_PER_SEC / HZ) * j; +#else + return div_u64(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); +#endif +} +EXPORT_SYMBOL(jiffies64_to_msecs); + /** * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 * -- 2.16.2