2019-02-27 09:40:55

by Li RongQing

Subject: [PATCH] time: Introduce jiffies64_to_msecs()

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 <[email protected]>
---
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

2019-02-27 11:19:15

by Thomas Gleixner

Subject: Re: [PATCH] time: Introduce jiffies64_to_msecs()

On Wed, 27 Feb 2019, Li RongQing wrote:

> there is a similar helper in net/netfilter/nf_tables_api.c,
> this maybe become a common request someday.

Maybe is not a really good justification for adding that. At least you
should provide a patch which replaces the instance in the netfilter code.

Thanks,

tglx

2019-02-28 01:30:58

by Li RongQing

Subject: 答复: [PATCH] time: Introduce jiffies64_to_ms ecs()

> -----?ʼ?ԭ??-----
> ??????: Thomas Gleixner [mailto:[email protected]]
> ????ʱ??: 2019??2??27?? 19:18
> ?ռ???: Li,Rongqing <[email protected]>
> ????: [email protected]; [email protected];
> [email protected]; [email protected]
> ????: Re: [PATCH] time: Introduce jiffies64_to_msecs()
>
> On Wed, 27 Feb 2019, Li RongQing wrote:
>
> > there is a similar helper in net/netfilter/nf_tables_api.c, this maybe
> > become a common request someday.
>
> Maybe is not a really good justification for adding that. At least you should
> provide a patch which replaces the instance in the netfilter code.
>
> Thanks,
>


OK, I will send V2

Thanks
-rongqing