Re: [PATCH net-next v2 1/6] devlink: Add new "io_eq_size" generic device param

[Jiri Pirko <jiri@resnulli.us>]

Wed, Dec 08, 2021 at 08:00:01AM CET, shayd@nvidia.com wrote:
>Add new device generic parameter to determine the size of the
>I/O completion EQs.
>
>For example, to reduce I/O EQ size to 64, execute:
>$ devlink dev param set pci/0000:06:00.0 \
>              name io_eq_size value 64 cmode driverinit
>$ devlink dev reload pci/0000:06:00.0
>
>Signed-off-by: Shay Drory <shayd@nvidia.com>
>Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
>---
> Documentation/networking/devlink/devlink-params.rst | 3 +++
> include/net/devlink.h                               | 4 ++++
> net/core/devlink.c                                  | 5 +++++
> 3 files changed, 12 insertions(+)
>
>diff --git a/Documentation/networking/devlink/devlink-params.rst b/Documentation/networking/devlink/devlink-params.rst
>index b7dfe693a332..cd9342305a13 100644
>--- a/Documentation/networking/devlink/devlink-params.rst
>+++ b/Documentation/networking/devlink/devlink-params.rst
>@@ -129,3 +129,6 @@ own name.
>        will NACK any attempt of other host to reset the device. This parameter
>        is useful for setups where a device is shared by different hosts, such
>        as multi-host setup.
>+   * - ``io_eq_size``
>+     - u16

Hmm, I wonder if this wouldn't be better to have it 32bits which might
be future safe.

Otherwise, this looks fine.


>+     - Control the size of I/O completion EQs.
>diff --git a/include/net/devlink.h b/include/net/devlink.h
>index 3276a29f2b81..61efa45b8786 100644
>--- a/include/net/devlink.h
>+++ b/include/net/devlink.h
>@@ -459,6 +459,7 @@ enum devlink_param_generic_id {
> 	DEVLINK_PARAM_GENERIC_ID_ENABLE_RDMA,
> 	DEVLINK_PARAM_GENERIC_ID_ENABLE_VNET,
> 	DEVLINK_PARAM_GENERIC_ID_ENABLE_IWARP,
>+	DEVLINK_PARAM_GENERIC_ID_IO_EQ_SIZE,
> 
> 	/* add new param generic ids above here*/
> 	__DEVLINK_PARAM_GENERIC_ID_MAX,
>@@ -511,6 +512,9 @@ enum devlink_param_generic_id {
> #define DEVLINK_PARAM_GENERIC_ENABLE_IWARP_NAME "enable_iwarp"
> #define DEVLINK_PARAM_GENERIC_ENABLE_IWARP_TYPE DEVLINK_PARAM_TYPE_BOOL
> 
>+#define DEVLINK_PARAM_GENERIC_IO_EQ_SIZE_NAME "io_eq_size"
>+#define DEVLINK_PARAM_GENERIC_IO_EQ_SIZE_TYPE DEVLINK_PARAM_TYPE_U16
>+
> #define DEVLINK_PARAM_GENERIC(_id, _cmodes, _get, _set, _validate)	\
> {									\
> 	.id = DEVLINK_PARAM_GENERIC_ID_##_id,				\
>diff --git a/net/core/devlink.c b/net/core/devlink.c
>index db3b52110cf2..0d4e63d11585 100644
>--- a/net/core/devlink.c
>+++ b/net/core/devlink.c
>@@ -4466,6 +4466,11 @@ static const struct devlink_param devlink_param_generic[] = {
> 		.name = DEVLINK_PARAM_GENERIC_ENABLE_IWARP_NAME,
> 		.type = DEVLINK_PARAM_GENERIC_ENABLE_IWARP_TYPE,
> 	},
>+	{
>+		.id = DEVLINK_PARAM_GENERIC_ID_IO_EQ_SIZE,
>+		.name = DEVLINK_PARAM_GENERIC_IO_EQ_SIZE_NAME,
>+		.type = DEVLINK_PARAM_GENERIC_IO_EQ_SIZE_TYPE,
>+	},
> };
> 
> static int devlink_param_generic_verify(const struct devlink_param *param)
>-- 
>2.21.3
>