lkml.org 
[lkml]   [2022]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH net-next 1/4] time64.h: define PSEC_PER_NSEC and use it in tc-taprio
Date
Hi Vincenzo,

On Mon, Jun 27, 2022 at 08:52:51AM +0100, Vincenzo Frascino wrote:
> Hi Vladimir,
>
> On 6/26/22 13:05, Vladimir Oltean wrote:
> > Time-sensitive networking code needs to work with PTP times expressed in
> > nanoseconds, and with packet transmission times expressed in
> > picoseconds, since those would be fractional at higher than gigabit
> > speed when expressed in nanoseconds.
> >
> > Convert the existing uses in tc-taprio to a PSEC_PER_NSEC macro.
> >
> > Cc: Andy Lutomirski <luto@kernel.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
> > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> > ---
> > include/vdso/time64.h | 1 +
> > net/sched/sch_taprio.c | 4 ++--
> > 2 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/vdso/time64.h b/include/vdso/time64.h
> > index b40cfa2aa33c..f1c2d02474ae 100644
> > --- a/include/vdso/time64.h
> > +++ b/include/vdso/time64.h
> > @@ -6,6 +6,7 @@
> > #define MSEC_PER_SEC 1000L
> > #define USEC_PER_MSEC 1000L
> > #define NSEC_PER_USEC 1000L
> > +#define PSEC_PER_NSEC 1000L
>
> Are you planning to use this definition in the vdso library code? If not, you
> should define PSEC_PER_NSEC in "include/linux/time64.h". The vdso namespace
> should contain only the definitions shared by the implementations of the kernel
> and of the vdso library.

I am not. I thought it would be ok to preserve the locality of
definitions by placing this near the others of its kind, since a macro
doesn't affect the compiled vDSO code in any way. But if you prefer, I
can create a new mini-section in linux/time64.h. Any preference on where
exactly to place that definition within the file?
\
 
 \ /
  Last update: 2022-06-27 10:51    [W:0.057 / U:0.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site