[RFC PATCH v3 00/39] ACPI/arm64: add support for virtual cpuhotplug

[Russell King (Oracle)]

On Mon, Dec 04, 2023 at 06:23:02PM +0000, Russell King (Oracle) wrote:
> On Tue, Oct 24, 2023 at 08:26:58PM +0200, Rafael J. Wysocki wrote:
> > On Tue, Oct 24, 2023 at 5:15 PM Russell King (Oracle)
> > <linux at armlinux.org.uk> wrote:
> > >
> > > Hi,
> > >
> > > I'm posting James' patch set updated with most of the review comments
> > > from his RFC v2 series back in September. Individual patches have a
> > > changelog attached at the bottom of the commit message. Those which
> > > I have finished updating have my S-o-b on them, those which still have
> > > outstanding review comments from RFC v2 do not. In some of these cases
> > > I've asked questions and am waiting for responses.
> > >
> > > I'm posting this as RFC v3 because there's still some unaddressed
> > > comments and it's clearly not ready for merging. Even if it was ready
> > > to be merged, it is too late in this development cycle to be taking
> > > this change in, so there would be little point posting it non-RFC.
> > > Also James stated that he's waiting for confirmation from the
> > > Kubernetes/Kata folk - I have no idea what the status is there.
> > >
> > > I will be sending each patch individually to a wider audience
> > > appropriate for that patch - apologies to those missing out on this
> > > cover message. I have added more mailing lists to the series with the
> > > exception of the acpica list in a hope of this cover message also
> > > reaching those folk.
> > >
> > > The changes that aren't included are:
> > >
> > > 1. Updates for my patch that was merged via Thomas (thanks!):
> > >    c4dd854f740c cpu-hotplug: Provide prototypes for arch CPU registration
> > >    rather than having this change spread through James' patches.
> > >
> > > 2. New patch - simplification of PA-RISC's smp_prepare_boot_cpu()
> > >
> > > 3. Moved "ACPI: Use the acpi_device_is_present() helper in more places"
> > >    and "ACPI: Rename acpi_scan_device_not_present() to be about
> > >    enumeration" to the beginning of the series - these two patches are
> > >    already queued up for merging into 6.7.
> > >
> > > 4. Moved "arm64, irqchip/gic-v3, ACPI: Move MADT GICC enabled check into
> > >    a helper" to the beginning of the series, which has been submitted,
> > >    but as yet the fate of that posting isn't known.
> > >
> > > The first four patches in this series are provided for completness only.
> > >
> > > There is an additional patch in James' git tree that isn't in the set
> > > of patches that James posted: "ACPI: processor: Only call
> > > arch_unregister_cpu() if HOTPLUG_CPU is selected" which looks to me to
> > > be a workaround for arch_unregister_cpu() being under the ifdef. I've
> > > commented on this on the RFC v2 posting making a suggestion, but as yet
> > > haven't had any response.
> > >
> > > I've included almost all of James' original covering body below the
> > > diffstat.
> > >
> > > The reason that I'm doing this is to help move this code forward so
> > > hopefully it can be merged - which is why I have been keen to dig out
> > > from James' patches anything that can be merged and submit it
> > > separately, since this is a feature for which some users have a
> > > definite need for.
> > 
> > I've gone through the series and there is at least one thing in it
> > that concerns me a lot and some others that at least appear to be
> > really questionable.
> > 
> > I need more time to send comments which I'm not going to do before the
> > 6.7 merge window (sorry), but from what I can say right now, this is
> > not looking good.
> 
> Hi Rafael,
> 
> Will you be able to send your comments, so that we can find out what
> your other concerns are please? I'm getting questions from interested
> parties who want to know what your concerns are.
> 
> Nothing much has changed to the ACPI changes, so I think it's still
> valid to have the comments back for this.

Hi Rafael,

Another gentle prod on this...

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