On Thu, Jan 17, 2019 at 3:41 AM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > On Wed, Jan 16, 2019 at 6:59 PM Keith Busch <keith.busch@xxxxxxxxx> wrote: > > > > Add entries for memory initiator and target node class attributes. > > > > Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx> > > I would recommend combining this with the previous patch, as the way > it is now I need to look at two patches at the time. :-) > > > --- > > Documentation/ABI/stable/sysfs-devices-node | 25 ++++++++++++++++++++++++- > > 1 file changed, 24 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node > > index 3e90e1f3bf0a..a9c47b4b0eee 100644 > > --- a/Documentation/ABI/stable/sysfs-devices-node > > +++ b/Documentation/ABI/stable/sysfs-devices-node > > @@ -90,4 +90,27 @@ Date: December 2009 > > Contact: Lee Schermerhorn <lee.schermerhorn@xxxxxx> > > Description: > > The node's huge page size control/query attributes. > > - See Documentation/admin-guide/mm/hugetlbpage.rst > > \ No newline at end of file > > + See Documentation/admin-guide/mm/hugetlbpage.rst > > + > > +What: /sys/devices/system/node/nodeX/classY/ > > +Date: December 2018 > > +Contact: Keith Busch <keith.busch@xxxxxxxxx> > > +Description: > > + The node's relationship to other nodes for access class "Y". > > + > > +What: /sys/devices/system/node/nodeX/classY/initiator_nodelist > > +Date: December 2018 > > +Contact: Keith Busch <keith.busch@xxxxxxxxx> > > +Description: > > + The node list of memory initiators that have class "Y" access > > + to this node's memory. CPUs and other memory initiators in > > + nodes not in the list accessing this node's memory may have > > + different performance. > > This does not follow the general "one value per file" rule of sysfs (I > know that there are other sysfs files with more than one value in > them, but it is better to follow this rule as long as that makes > sense). > > > + > > +What: /sys/devices/system/node/nodeX/classY/target_nodelist > > +Date: December 2018 > > +Contact: Keith Busch <keith.busch@xxxxxxxxx> > > +Description: > > + The node list of memory targets that this initiator node has > > + class "Y" access. Memory accesses from this node to nodes not > > + in this list may have differet performance. > > -- > > Same here. > > And if you follow the recommendation given in the previous message > (add "initiators" and "targets" subdirs under "classX"), you won't > even need the two files above. This recommendation is in conflict with Greg's feedback about kobject usage. If these are just "vanity" subdirs I think it's better to have a multi-value sysfs file. This "list" style is already commonplace for the /sys/devices/system hierarchy.