Re: [PATCH 39/47] clocksource: hyper-v: Move CPUHP_AP_HYPERV_TIMER_STARTING post stop_machine()

[Frederic Weisbecker]

Le Fri, Nov 06, 2026 at 03:37:26PM +0530, Naman Jain a écrit :
> 
> 
> On 11/5/2026 10:00 PM, Frederic Weisbecker wrote:
> > Between CPUHP_TEARDOWN_CPU and CPUHP_AP_OFFLINE, stop_machine executes
> > all the teardown callbacks while stopping all CPUs in the system. This
> > doesn't mix-up well with running RT or isolated tasks.
> > 
> > In order to transition smoothly from global stop_machine to finer
> > grained synchronization between teardown callbacks and the other CPUs,
> > a new stop machine post function has been introduced to be executed
> > after the main one with IRQs still disabled while other CPUs can exit
> > stop_machine().
> > 
> > The teardown callback here simply performs timer and IRQ disablement,
> > both of which can run concurrently with other CPUs.
> > 
> > Move it to post stop_machine() accordingly.
> > 
> > Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
> > ---
> >   kernel/cpu.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/kernel/cpu.c b/kernel/cpu.c
> > index 93b8498e26c4..b49b67ef5ecb 100644
> 
> I am unable to correlate the commit message with the change and could not
> find the rest of the series on lore to get more context.

Sorry about that. I couldn't CC everyone to the motherpatch so I tried
to bring as much context as I could to each individual follow-up's changelog.
Probably that wasn't enough.

So here is the cover letter that explains the whole intent:

https://lore.kernel.org/lkml/20261105163045.38862-1-frederic@xxxxxxxxxx/

And the patch that does the initial infrastructure change to stop machine:

https://lore.kernel.org/lkml/20261105163045.38862-2-frederic@xxxxxxxxxx/

Thanks.

-- 
Frederic Weisbecker
SUSE Labs