[PATCH] time: export nsec_to_clock_t

[PATCH] time: export nsec_to_clock_t

[Arnd Bergmann]

nsec_to_clock_t was traditionally used only in the core kernel, now we
have a sysfs file that needs it from a loadable module, causing a
link-time error:

ERROR: "nsec_to_clock_t" [drivers/thermal/thermal_sys.ko] undefined!

This exports the function the same way that we do for related interfaces.

Fixes: 96cea33badc5 ("thermal: Add cooling device's statistics in sysfs")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 kernel/time/time.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/time/time.c b/kernel/time/time.c
index 6fa99213fc72..97a262531f68 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -768,6 +768,7 @@ u64 nsec_to_clock_t(u64 x)
 	return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ);
 #endif
 }
+EXPORT_SYMBOL(nsec_to_clock_t);
 
 u64 jiffies64_to_nsecs(u64 j)
 {
-- 
2.9.0

Re: [PATCH] time: export nsec_to_clock_t

[Zhang Rui]

On 三, 2018-03-28 at 16:11 +0200, Arnd Bergmann wrote:
> nsec_to_clock_t was traditionally used only in the core kernel, now
> we
> have a sysfs file that needs it from a loadable module, causing a
> link-time error:
> 
> ERROR: "nsec_to_clock_t" [drivers/thermal/thermal_sys.ko] undefined!
> 
> This exports the function the same way that we do for related
> interfaces.
> 
> Fixes: 96cea33badc5 ("thermal: Add cooling device's statistics in
> sysfs")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for the fix.
can I take this patch through thermal tree?

thanks,
rui
> ---
>  kernel/time/time.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/time/time.c b/kernel/time/time.c
> index 6fa99213fc72..97a262531f68 100644
> --- a/kernel/time/time.c
> +++ b/kernel/time/time.c
> @@ -768,6 +768,7 @@ u64 nsec_to_clock_t(u64 x)
>  	return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2))
> / USER_HZ);
>  #endif
>  }
> +EXPORT_SYMBOL(nsec_to_clock_t);
>  
>  u64 jiffies64_to_nsecs(u64 j)
>  {

Re: [PATCH] time: export nsec_to_clock_t

[Thomas Gleixner]

[-- Attachment #1: Type: text/plain, Size: 845 bytes --]

On Thu, 29 Mar 2018, Zhang Rui wrote:
> On 三, 2018-03-28 at 16:11 +0200, Arnd Bergmann wrote:
> > nsec_to_clock_t was traditionally used only in the core kernel, now
> > we
> > have a sysfs file that needs it from a loadable module, causing a
> > link-time error:
> > 
> > ERROR: "nsec_to_clock_t" [drivers/thermal/thermal_sys.ko] undefined!
> > 
> > This exports the function the same way that we do for related
> > interfaces.
> > 
> > Fixes: 96cea33badc5 ("thermal: Add cooling device's statistics in
> > sysfs")
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> Thanks for the fix.
> can I take this patch through thermal tree?

Well, the question is what's the point of that?

Why does a new interface expose time in state in clock_t instead in normal
time units, e.g. nsec/usec/msec ?

That makes no sense whatsoever.

Thanks,

	tglx

Re: [PATCH] time: export nsec_to_clock_t

[Viresh Kumar]

On 29-03-18, 21:11, Thomas Gleixner wrote:
> On Thu, 29 Mar 2018, Zhang Rui wrote:
> > On 三, 2018-03-28 at 16:11 +0200, Arnd Bergmann wrote:
> > > nsec_to_clock_t was traditionally used only in the core kernel, now
> > > we
> > > have a sysfs file that needs it from a loadable module, causing a
> > > link-time error:
> > > 
> > > ERROR: "nsec_to_clock_t" [drivers/thermal/thermal_sys.ko] undefined!
> > > 
> > > This exports the function the same way that we do for related
> > > interfaces.
> > > 
> > > Fixes: 96cea33badc5 ("thermal: Add cooling device's statistics in
> > > sysfs")
> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > 
> > Thanks for the fix.
> > can I take this patch through thermal tree?
> 
> Well, the question is what's the point of that?
> 
> Why does a new interface expose time in state in clock_t instead in normal
> time units, e.g. nsec/usec/msec ?

The initial patch was displaying the values in msec, but eduardo asked the units
to be consistent with how cpufreq shows it, i.e. clock_t.

https://lkml.kernel.org/r/20180112174606.GA11076@localhost.localdomain 

Anyway I will resend the patch and move back to msec. Thanks.

-- 
viresh