Re: [Xenomai-core] [PATCH 4/7] nucleus: Add CLOCK_HOST_REALTIME bits to nkvdso
Gilles Chanteperdrix wrote: > Wolfgang Mauerer wrote: >> Gilles Chanteperdrix wrote: >>> Wolfgang Mauerer wrote: Augment the shared vdso page with all data required to implement a clock CLOCK_HOST_REALTIME that provides time information synchronised with the NTP-corrected time in the Linux kernel. The definition of the hostrt data is placed in a separate head file so that we can use it irregardless of pervasive rt support is compiled in or not. >>> Ok. Would not it be more simple to define the nkvdso even without >>> pervasive support? >> Thought about that, but having a shared kernel/userland object >> without pervasive RT support seemed a bit unnatural to me. > > The idea would be to have a static nkvdso in the non-pervasive case, we > do not need the mapping stuff. But at least, if we do this once and for > all for nkvdso, we will not have to repeat the code which handles the > non-pervasive case for all the data in nkvdso which need to exist in > that case. okay, let's do it like this. Might also save a couple of ifdefs. Regards, Wolfgang ___ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
Re: [Xenomai-core] [PATCH 4/7] nucleus: Add CLOCK_HOST_REALTIME bits to nkvdso
Wolfgang Mauerer wrote: > Gilles Chanteperdrix wrote: >> Wolfgang Mauerer wrote: >>> Augment the shared vdso page with all data required to >>> implement a clock CLOCK_HOST_REALTIME that provides time >>> information synchronised with the NTP-corrected time >>> in the Linux kernel. >>> >>> The definition of the hostrt data is placed in a separate >>> head file so that we can use it irregardless of pervasive >>> rt support is compiled in or not. >> Ok. Would not it be more simple to define the nkvdso even without >> pervasive support? > > Thought about that, but having a shared kernel/userland object > without pervasive RT support seemed a bit unnatural to me. The idea would be to have a static nkvdso in the non-pervasive case, we do not need the mapping stuff. But at least, if we do this once and for all for nkvdso, we will not have to repeat the code which handles the non-pervasive case for all the data in nkvdso which need to exist in that case. -- Gilles. ___ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
Re: [Xenomai-core] [PATCH 4/7] nucleus: Add CLOCK_HOST_REALTIME bits to nkvdso
Gilles Chanteperdrix wrote: > Wolfgang Mauerer wrote: >> Augment the shared vdso page with all data required to >> implement a clock CLOCK_HOST_REALTIME that provides time >> information synchronised with the NTP-corrected time >> in the Linux kernel. >> >> The definition of the hostrt data is placed in a separate >> head file so that we can use it irregardless of pervasive >> rt support is compiled in or not. > > Ok. Would not it be more simple to define the nkvdso even without > pervasive support? Thought about that, but having a shared kernel/userland object without pervasive RT support seemed a bit unnatural to me. > >> +#if defined(CONFIG_XENO_OPT_HOSTRT) && !defined(CONFIG_XENO_OPT_PERVASIVE) >> +nkhostrt_data = xnarch_alloc_host_mem(sizeof(struct >> xnarch_hostrt_data)); > > should be sizeof(*nkhostrt_data) > > But why a dynamic allocation at all? not really required, can also make it static if you prefer. Best regards, Wolfgang ___ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
Re: [Xenomai-core] [PATCH 4/7] nucleus: Add CLOCK_HOST_REALTIME bits to nkvdso
Wolfgang Mauerer wrote: > Augment the shared vdso page with all data required to > implement a clock CLOCK_HOST_REALTIME that provides time > information synchronised with the NTP-corrected time > in the Linux kernel. > > The definition of the hostrt data is placed in a separate > head file so that we can use it irregardless of pervasive > rt support is compiled in or not. Ok. Would not it be more simple to define the nkvdso even without pervasive support? > +#if defined(CONFIG_XENO_OPT_HOSTRT) && !defined(CONFIG_XENO_OPT_PERVASIVE) > + nkhostrt_data = xnarch_alloc_host_mem(sizeof(struct > xnarch_hostrt_data)); should be sizeof(*nkhostrt_data) But why a dynamic allocation at all? -- Gilles. ___ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
