On Fri, Jan 18, 2019 at 3:22 AM Jonathan Cameron <jonathan.cameron@xxxxxxxxxx> wrote: > > On Wed, 16 Jan 2019 10:57:56 -0700 > Keith Busch <keith.busch@xxxxxxxxx> wrote: > > > Add entries for memory initiator and target node class attributes. > > > > Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx> > > --- > > 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. > > + > > +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. > > Different performance from what? In the other thread we established that > these target_nodelists are kind of a backwards reference, they all have > their characteristics anyway. Perhaps this just needs to say: > "Memory access from this node to these targets may have different performance"? > > i.e. Don't make the assumption I did that they should all be the same! I think a clarification of "class" is needed in this context. A "class" is the the set of initiators that have the same rated performance to a given target set. In other words "class" is a tuple of (performance profile, initiator set, target set). Different performance creates a different tuple / class.
