Re: [PATCH V6 7/7] docs: mm: numaperf.rst Add brief description for access class 1.

From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Brice Goglin <brice.goglin@gmail.com>
Cc: <linux-mm@kvack.org>, <linux-acpi@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>, <x86@kernel.org>,
	Keith Busch <keith.busch@intel.com>, <jglisse@redhat.com>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>, <linuxarm@huawei.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	Dan Williams <dan.j.williams@intel.com>,
	Tao Xu <tao3.xu@intel.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Hanjun Guo <guohanjun@huawei.com>,
	Sudeep Holla <sudeep.holla@arm.com>
Subject: Re: [PATCH V6 7/7] docs: mm: numaperf.rst Add brief description for access class 1.
Date: Wed, 18 Dec 2019 14:37:25 +0000	[thread overview]
Message-ID: <20191218143725.00002f6f@Huawei.com> (raw)
In-Reply-To: <4cf4e790-cacb-b250-bf28-5ba540eb0dc7@gmail.com>

On Wed, 18 Dec 2019 12:34:34 +0100
Brice Goglin <brice.goglin@gmail.com> wrote:

> Le 16/12/2019 à 16:38, Jonathan Cameron a écrit :
> > Try to make minimal changes to the document which already describes
> > access class 0 in a generic fashion (including IO initiatiors that
> > are not CPUs).
> >
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > ---
> >  Documentation/admin-guide/mm/numaperf.rst | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/Documentation/admin-guide/mm/numaperf.rst b/Documentation/admin-guide/mm/numaperf.rst
> > index a80c3c37226e..327c0d72692d 100644
> > --- a/Documentation/admin-guide/mm/numaperf.rst
> > +++ b/Documentation/admin-guide/mm/numaperf.rst
> > @@ -56,6 +56,11 @@ nodes' access characteristics share the same performance relative to other
> >  linked initiator nodes. Each target within an initiator's access class,
> >  though, do not necessarily perform the same as each other.
> >  
> > +The access class "1" is used to allow differentiation between initiators
> > +that are CPUs and hence suitable for generic task scheduling, and
> > +IO initiators such as GPUs and CPUs.  Unlike access class 0, only
> > +nodes containing CPUs are considered.
> > +
> >  ================
> >  NUMA Performance
> >  ================
> > @@ -88,6 +93,9 @@ The latency attributes are provided in nanoseconds.
> >  The values reported here correspond to the rated latency and bandwidth
> >  for the platform.
> >  
> > +Access class 0, takes the same form, but only includes values for CPU to
> > +memory activity.  
> 
> 
> Shouldn't this be "class 1" here?
> 
Good point.

Jonathan

> Both hunks look contradictory to me.
> 
> Brice
> 
>