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Date:   Tue, 5 Feb 2019 07:48:15 -0700
From:   Keith Busch <keith.busch@intel.com>
To:     "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Hansen, Dave" <dave.hansen@intel.com>,
        "Williams, Dan J" <dan.j.williams@intel.com>
Subject: Re: [PATCHv5 04/10] node: Link memory nodes to their compute nodes
Message-ID: <20190205144815.GA28023@localhost.localdomain>
References: <20190124230724.10022-1-keith.busch@intel.com>
 <20190124230724.10022-5-keith.busch@intel.com>
 <CAJZ5v0jE_gRT5WgpQYwZQmx6N5G+axymbSySb2Nk8Q0OGeNt9A@mail.gmail.com>
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On Tue, Feb 05, 2019 at 04:33:27AM -0800, Rafael J. Wysocki wrote:
> On Fri, Jan 25, 2019 at 12:08 AM Keith Busch <keith.busch@intel.com> wrote:
> > +/**
> > + * struct node_access_nodes - Access class device to hold user visible
> > + *                           relationships to other nodes.
> > + * @dev:       Device for this memory access class
> > + * @list_node: List element in the node's access list
> > + * @access:    The access class rank
> > + */
> > +struct node_access_nodes {
> > +       struct device           dev;
> 
> I'm not sure if the entire struct device is needed here.
> 
> It looks like what you need is the kobject part of it only and you can
> use a kobject directly here:
> 
> struct kobject        kobj;
> 
> Then, you can register that under the node's kobject using
> kobject_init_and_add() and you can create attr groups under a kobject
> using sysfs_create_groups(), which is exactly what device_add_groups()
> does.
> 
> That would allow you to avoid allocating extra memory to hold the
> entire device structure and the extra empty "power" subdirectory added
> by device registration would not be there.

This is conflicting with Greg's feedback from the first version of
this series:

  https://lore.kernel.org/lkml/20181126190619.GA32595@kroah.com/

Do you still recommend using kobject?