Re: [PATCH v5 0/4] pseries: Add cede support for cpu-offline

Benjamin Herrenschmidt
2009-11-24T03:37:37Z

On Fri, 2009-10-30 at 10:52 +0530, Gautham R Shenoy wrote:
> Hi,
>
> This is version 5 of patch series that provides a framework to choose the
> state a pseries CPU must be put to when it is offlined.
>
> Previous versions can be found here:
> Version 4: http://lkml.org/lkml/2009/10/9/59
> Version 3: http://lkml.org/lkml/2009/9/15/164
> Version 2: http://lkml.org/lkml/2009/8/28/102
> Version 1: http://lkml.org/lkml/2009/8/6/236
>
> Changes from the previous version include:
> - Rebased against Nathan Fontenot's latest "pseries kernel handling of dynamic
> logical paritioning v4" patches found here:
> http://lkml.org/lkml/2009/10/21/98

I can't merge them right now because afaik, Nathan patches are still not
quite ready. So we need to either get a final version of Nathan patches
something like tomorrow or you need to rebase your series on current
-next by the end of the week, or I'm afraid it's going to miss the next
merge window.

Cheers,
Ben.

> - Added boot-time option to disable putting the offlined vcpus into an
> extended H_CEDE state.
>
> - Addressed Ben's comments regarding the if-else sequencing in
> pseries_mach_cpu_die().
>
> - Addition of comments for pseries_cpu_die() to distinguish it from
> pseries_mach_cpu_die()
>
> Also,
>
> - This approach addresses Peter Z's objections regarding layering
> violations. The user simply offlines the cpu and doesn't worry about what
> state the CPU should be put into. That part is automatically handled by the
> kernel.
>
> - It does not add any additional sysfs interface instead uses the existing
> sysfs interface to offline CPUs.
>
> - On platforms which do not have support for ceding the vcpu with a
> latency specifier value, the offlining mechanism defaults to the current
> method of calling rtas_stop_self().
>
> The patchset has been tested on the available pseries platforms and it works
> as per the expectations. I believe that the patch set is ready for inclusion.
> ---
>
> Gautham R Shenoy (4):
> pseries: Serialize cpu hotplug operations during deactivate Vs deallocate
> pseries: Add code to online/offline CPUs of a DLPAR node.
> pSeries: Add hooks to put the CPU into an appropriate offline state
> pSeries: extended_cede_processor() helper function.
>
>
> Documentation/cpu-hotplug.txt | 6 +
> arch/powerpc/include/asm/lppaca.h | 9 +
> arch/powerpc/platforms/pseries/dlpar.c | 129 ++++++++++++++++
> arch/powerpc/platforms/pseries/hotplug-cpu.c | 182 ++++++++++++++++++++++-
> arch/powerpc/platforms/pseries/offline_states.h | 18 ++
> arch/powerpc/platforms/pseries/plpar_wrappers.h | 22 +++
> arch/powerpc/platforms/pseries/smp.c | 19 ++
> arch/powerpc/xmon/xmon.c | 3
> drivers/base/cpu.c | 2
> include/linux/cpu.h | 13 ++
> 10 files changed, 387 insertions(+), 16 deletions(-)
> create mode 100644 arch/powerpc/platforms/pseries/offline_states.h
>