RE: [NDCTL PATCH v3 0/3] ndctl: Add support of qos_class for CXL CLI

From: Dan Williams <dan.j.williams@intel.com>
To: Dave Jiang <dave.jiang@intel.com>, <linux-cxl@vger.kernel.org>,
	<nvdimm@lists.linux.dev>
Cc: <vishal.l.verma@intel.com>
Subject: RE: [NDCTL PATCH v3 0/3] ndctl: Add support of qos_class for CXL CLI
Date: Thu, 25 Jan 2024 13:16:21 -0800	[thread overview]
Message-ID: <65b2cfa5d3541_37ad2947b@dwillia2-xfh.jf.intel.com.notmuch> (raw)
In-Reply-To: <170612961495.2745924.4942817284170536877.stgit@djiang5-mobl3>

Dave Jiang wrote:
> Hi Vishal,
> With the QoS class series merged to the v6.8 kernel, can you please review and
> apply this series to ndctl if acceptable?
> 
> v3:
> - Rebase against latest ndctl/pending branch.
> 
> The series adds support for the kernel enabling of QoS class in the v6.8
> kernel. The kernel exports a qos_class token for the root decoders (CFMWS) and as
> well as for the CXL memory devices. The qos_class exported for a device is
> calculated by the driver during device probe. Currently a qos_class is exported
> for the volatile partition (ram) and another for the persistent partition (pmem).
> In the future qos_class will be exported for DCD regions. Display of qos_class is
> through the CXL CLI list command with -vvv for extra verbose.
> 
> A qos_class check as also been added for region creation. A warning is emitted
> when the qos_class of a memory range of a CXL memory device being included in
> the CXL region assembly does not match the qos_class of the root decoder. Options
> are available to suppress the warning or to fail the region creation. This
> enabling provides a guidance on flagging memory ranges being used is not
> optimal for performance for the CXL region to be formed.
> 
> ---
> 
> Dave Jiang (3):
>       ndctl: cxl: Add QoS class retrieval for the root decoder
>       ndctl: cxl: Add QoS class support for the memory device
>       ndctl: cxl: add QoS class check for CXL region creation
> 
> 
>  Documentation/cxl/cxl-create-region.txt |  9 ++++
>  cxl/filter.h                            |  4 ++
>  cxl/json.c                              | 46 ++++++++++++++++-
>  cxl/lib/libcxl.c                        | 62 +++++++++++++++++++++++
>  cxl/lib/libcxl.sym                      |  3 ++
>  cxl/lib/private.h                       |  3 ++
>  cxl/libcxl.h                            | 10 ++++
>  cxl/list.c                              |  1 +
>  cxl/region.c                            | 67 ++++++++++++++++++++++++-
>  util/json.h                             |  1 +
>  10 files changed, 204 insertions(+), 2 deletions(-)

This needs changes to test/cxl-topology.sh to validate that the
qos_class file pops in the right place per and has prepopulated values
per cxl_test expectation.