Re: ntp_init() looks like a nop

On Mon, Feb 7, 2022 at 8:20 AM Konstantin Belousov <kostikbel@gmail.com>
wrote:

> On Mon, Feb 07, 2022 at 04:04:56PM +0100, Sebastian Huber wrote:
> > Hello,
> >
> > I review currently the kern_ntptime.c module since I would like to use
> it in
> > RTEMS. I have a question to ntp_init():
> >
> > /*
> >  * ntp_init() - initialize variables and structures
> >  *
> >  * This routine must be called after the kernel variables hz and tick
> >  * are set or changed and before the next tick interrupt. In this
> >  * particular implementation, these values are assumed set elsewhere in
> >  * the kernel. The design allows the clock frequency and tick interval
> >  * to be changed while the system is running. So, this routine should
> >  * probably be integrated with the code that does that.
> >  */
> > static void
> > ntp_init(void)
> > {
> >
> >       /*
> >        * The following variables are initialized only at startup. Only
> >        * those structures not cleared by the compiler need to be
> >        * initialized, and these only in the simulator. In the actual
> >        * kernel, any nonzero values here will quickly evaporate.
> >        */
> >       L_CLR(time_offset);
> >       L_CLR(time_freq);
> > #ifdef PPS_SYNC
> >       pps_tf[0].tv_sec = pps_tf[0].tv_nsec = 0;
> >       pps_tf[1].tv_sec = pps_tf[1].tv_nsec = 0;
> >       pps_tf[2].tv_sec = pps_tf[2].tv_nsec = 0;
> >       pps_fcount = 0;
> >       L_CLR(pps_freq);
> > #endif /* PPS_SYNC */
> > }
> >
> > SYSINIT(ntpclocks, SI_SUB_CLOCKS, SI_ORDER_MIDDLE, ntp_init, NULL);
> >
> > The ntp_init() function sets a couple of global variables to zero. These
> > variables should be in the .bss section. Are they not already cleared
> during
> > the kernel loading?
> This is nop indeed, be it linked in kernel, or loaded as a module.
>

I just looked at the posted patch, and I concur.

Warner