Re: [PATCH v2] doc: Add CPU Isolation documentation

[Frederic Weisbecker <frederic@kernel.org>]

Le Thu, Mar 26, 2026 at 02:42:32PM -0700, Randy Dunlap a écrit :
> (Just some small comments -- take them or not.)
> 
> On 3/26/26 7:00 AM, Frederic Weisbecker wrote:
> > nohz_full was introduced in v3.10 in 2013, which means this
> > documentation is overdue for 13 years.
> > 
> > Fortunately Paul wrote a part of the needed documentation a while ago,
> > especially concerning nohz_full in Documentation/timers/no_hz.rst and
> > also about per-CPU kthreads in
> > Documentation/admin-guide/kernel-per-CPU-kthreads.rst
> > 
> > Introduce a new page that gives an overview of CPU isolation in general.
> > 
> > Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
> > ---
> > v2:
> >    - Fix links and code blocks (Bagas and Sebastian)
> >    - Isolation is not only about userspace, rephrase accordingly (Valentin)
> >    - Paste BIOS issues suggestion from Valentin
> >    - Include the whole rtla suite (Valentin)
> >    - Rephrase a few details (Waiman)
> >    - Talk about RCU induced overhead rather than slower RCU (Sebastian)
> > 
> >  Documentation/admin-guide/cpu-isolation.rst | 357 ++++++++++++++++++++
> >  Documentation/admin-guide/index.rst         |   1 +
> >  2 files changed, 358 insertions(+)
> >  create mode 100644 Documentation/admin-guide/cpu-isolation.rst
> > 
> > diff --git a/Documentation/admin-guide/cpu-isolation.rst b/Documentation/admin-guide/cpu-isolation.rst
> > new file mode 100644
> > index 000000000000..886dec79b056
> > --- /dev/null
> > +++ b/Documentation/admin-guide/cpu-isolation.rst
> > @@ -0,0 +1,357 @@
> > +.. SPDX-License-Identifier: GPL-2.0
> > +
> > +=============
> > +CPU Isolation
> > +=============
> > +
> > +Introduction
> > +============
> > +
> > +"CPU Isolation" means leaving a CPU exclusive to a given workload
> > +without any undesired code interference from the kernel.
> > +
> > +Those interferences, commonly pointed out as "noise", can be triggered
> 
> nit:                                            "noise,"

Thanks! I have applied all your suggestions, except this one for now because I don't
really understand the typo rule behind. Any hint?

-- 
Frederic Weisbecker
SUSE Labs