Re: [PATCH RFC v3 21/21] cpumask: Add enabled cpumask for present CPUs that can be brought online

Jonathan Cameron
2024-01-02T15:19:58Z

On Mon, 18 Dec 2023 12:14:14 +0000
"Russell King (Oracle)" <linux@armlinux.org.uk> wrote:

> On Fri, Dec 15, 2023 at 05:18:31PM +0000, Jonathan Cameron wrote:
> > On Wed, 13 Dec 2023 12:50:59 +0000
> > Russell King (Oracle) <rmk+kernel@armlinux.org.uk> wrote:
> >
> > > From: James Morse <james.morse@arm.com>
> > >
> > > The 'offline' file in sysfs shows all offline CPUs, including those
> > > that aren't present. User-space is expected to remove not-present CPUs
> > > from this list to learn which CPUs could be brought online.
> > >
> > > CPUs can be present but not-enabled. These CPUs can't be brought online
> > > until the firmware policy changes, which comes with an ACPI notification
> > > that will register the CPUs.
> > >
> > > With only the offline and present files, user-space is unable to
> > > determine which CPUs it can try to bring online. Add a new CPU mask
> > > that shows this based on all the registered CPUs.
> > >
> > > Signed-off-by: James Morse <james.morse@arm.com>
> > > Tested-by: Miguel Luis <miguel.luis@oracle.com>
> > > Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
> > > Tested-by: Jianyong Wu <jianyong.wu@arm.com>
> > > ---
> >
> > Needs docs
> > Documentation/ABI/testing/sysfs-devices-system-cpu
> > seems to have the rest of the similar entries.
>
> Any ideas what I put in there as "Date" ? It seems to me that we have
> little idea when this might be merged.. I could use the date of the
> commit (Nov 2022).
>

That's always a guess at best. Hopefully whoever picks this up
fixes the date up or asks for a new version with it fixed just before
they do.

J