Support dumping defer_hard_irqs for a NAPI ID.

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 Documentation/netlink/specs/netdev.yaml | 8 ++++++++
 include/uapi/linux/netdev.h             | 1 +
 net/core/netdev-genl.c                  | 5 +++++
 tools/include/uapi/linux/netdev.h       | 1 +
 4 files changed, 15 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index cf3e77c6fd5e..e4219bfff08d 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -252,6 +252,13 @@ attribute-sets:
         checks:
           min: 0
           max: s32-max
+      -
+        name: defer-hard-irqs
+        doc: The number of consecutive empty polls before IRQ deferral ends
+             and hardware IRQs are re-enabled.
+        type: u32
+        checks:
+          max: s32-max
   -
     name: queue
     attributes:
@@ -602,6 +609,7 @@ operations:
             - irq
             - pid
             - index
+            - defer-hard-irqs
       dump:
         request:
           attributes:
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index e06e33acb6fd..bcc95b7ebd92 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -122,6 +122,7 @@ enum {
 	NETDEV_A_NAPI_IRQ,
 	NETDEV_A_NAPI_PID,
 	NETDEV_A_NAPI_INDEX,
+	NETDEV_A_NAPI_DEFER_HARD_IRQS,
 
 	__NETDEV_A_NAPI_MAX,
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 9561841b9d2d..f1e505ad069f 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -160,6 +160,7 @@ static int
 netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 			const struct genl_info *info)
 {
+	int napi_defer_hard_irqs;
 	void *hdr;
 	pid_t pid;
 
@@ -191,6 +192,10 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 			goto nla_put_failure;
 	}
 
+	napi_defer_hard_irqs = napi_get_defer_hard_irqs(napi);
+	if (nla_put_s32(rsp, NETDEV_A_NAPI_DEFER_HARD_IRQS, napi_defer_hard_irqs))
+		goto nla_put_failure;
+
 	genlmsg_end(rsp, hdr);
 
 	return 0;
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 43742ac5b00d..43bb1aad9611 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -121,6 +121,7 @@ enum {
 	NETDEV_A_NAPI_ID,
 	NETDEV_A_NAPI_IRQ,
 	NETDEV_A_NAPI_PID,
+	NETDEV_A_NAPI_DEFER_HARD_IRQS,
 
 	__NETDEV_A_NAPI_MAX,
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
-- 
2.25.1

On Sun, Sep 08, 2024 at 04:06:38PM +0000, Joe Damato wrote:
> Support dumping defer_hard_irqs for a NAPI ID.
> 
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
>  Documentation/netlink/specs/netdev.yaml | 8 ++++++++
>  include/uapi/linux/netdev.h             | 1 +
>  net/core/netdev-genl.c                  | 5 +++++
>  tools/include/uapi/linux/netdev.h       | 1 +
>  4 files changed, 15 insertions(+)

[...]

> diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
> index 9561841b9d2d..f1e505ad069f 100644
> --- a/net/core/netdev-genl.c
> +++ b/net/core/netdev-genl.c
> @@ -160,6 +160,7 @@ static int
>  netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
>  			const struct genl_info *info)
>  {
> +	int napi_defer_hard_irqs;

I've already made this a u32 in my rfcv2 branch.

>  	void *hdr;
>  	pid_t pid;
>  
> @@ -191,6 +192,10 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
>  			goto nla_put_failure;
>  	}
>  
> +	napi_defer_hard_irqs = napi_get_defer_hard_irqs(napi);
> +	if (nla_put_s32(rsp, NETDEV_A_NAPI_DEFER_HARD_IRQS, napi_defer_hard_irqs))
> +		goto nla_put_failure;
> +
>  	genlmsg_end(rsp, hdr);
>  
>  	return 0;