Re: [PATCH v3 19/25] cxl/region/extent: Expose region extent information in sysfs

[Ira Weiny <ira.weiny@intel.com>]

Dave Jiang wrote:
> 
> 
> On 8/16/24 7:44 AM, ira.weiny@intel.com wrote:
> > From: Navneet Singh <navneet.singh@intel.com>
> > 
> > Extent information can be helpful to the user to coordinate memory usage
> > with the external orchestrator and FM.
> > 
> > Expose the details of region extents by creating the following
> > sysfs entries.
> > 
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> >         /sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> > 
> > Signed-off-by: Navneet Singh <navneet.singh@intel.com>
> > Co-developed-by: Ira Weiny <ira.weiny@intel.com>
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > 
> > ---
> > Changes:
> > [iweiny: split this out]
> > [Jonathan: add documentation for extent sysfs]
> > [Jonathan/djbw: s/label/tag]
> > [Jonathan/djbw: treat tag as uuid]
> > [djbw: use __ATTRIBUTE_GROUPS]
> > [djbw: make tag invisible if it is empty]
> > [djbw/iweiny: use conventional id names for extents; extentX.Y]
> > ---
> >  Documentation/ABI/testing/sysfs-bus-cxl | 13 ++++++++
> >  drivers/cxl/core/extent.c               | 58 +++++++++++++++++++++++++++++++++
> >  2 files changed, 71 insertions(+)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > index 3a5ee88e551b..e97e6a73c960 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > @@ -599,3 +599,16 @@ Description:
> >  		See Documentation/ABI/stable/sysfs-devices-node. access0 provides
> >  		the number to the closest initiator and access1 provides the
> >  		number to the closest CPU.
> > +
> > +What:		/sys/bus/cxl/devices/dax_regionX/extentX.Y/offset
> > +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/length
> > +		/sys/bus/cxl/devices/dax_regionX/extentX.Y/tag
> 
> I wonder consider an entry for each with their own descriptions, which seems to be the standard practice.

:-/  Except kind of for the access'.

What:           /sys/bus/cxl/devices/regionZ/accessY/read_bandwidth
                /sys/bus/cxl/devices/regionZ/accessY/write_banwidth

What:           /sys/bus/cxl/devices/regionZ/accessY/read_latency
                /sys/bus/cxl/devices/regionZ/accessY/write_latency

But I think you have a point.

Ira

> 
> DJ
> 

[snip]