[PATCH iproute2-next v3] rdma: display resource limits in curr/max format

[PATCH iproute2-next v3] rdma: display resource limits in curr/max format

[Tao Cui]

From: Tao Cui <cuitao@kylinos.cn>

Parse the new RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX netlink attribute
to show resource limits alongside current counts in curr/max format:

  Before: 0: mlx5_0: qp 123  cq 45  mr 200  pd 10
  After:  0: mlx5_0: qp 123/131072  cq 45/65536  mr 200/1000000  pd 10/32768

JSON output provides both current and max fields per resource type
(e.g. "qp": 123, "qp-max": 131072). Backward compatible: no output
change when kernel lacks the new attribute.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
---
 rdma/include/uapi/rdma/rdma_netlink.h |  5 +++++
 rdma/res.c                            | 21 ++++++++++++++++++++-
 rdma/utils.c                          |  1 +
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/rdma/include/uapi/rdma/rdma_netlink.h b/rdma/include/uapi/rdma/rdma_netlink.h
index 4356ec4a..e5b8b065 100644
--- a/rdma/include/uapi/rdma/rdma_netlink.h
+++ b/rdma/include/uapi/rdma/rdma_netlink.h
@@ -604,6 +604,11 @@ enum rdma_nldev_attr {
 	RDMA_NLDEV_ATTR_FRMR_POOL_PINNED_HANDLES,	/* u32 */
 	RDMA_NLDEV_ATTR_FRMR_POOL_KEY_KERNEL_VENDOR_KEY,	/* u64 */
 
+	/*
+	 * Resource summary entry maximum value.
+	 */
+	RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX,		/* u64 */
+
 	/*
 	 * Always the end
 	 */
diff --git a/rdma/res.c b/rdma/res.c
index 062f0007..046935e2 100644
--- a/rdma/res.c
+++ b/rdma/res.c
@@ -55,7 +55,26 @@ static int res_print_summary(struct nlattr **tb)
 
 		name = mnl_attr_get_str(nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_NAME]);
 		curr = mnl_attr_get_u64(nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR]);
-		res_print_u64(name, curr, nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR]);
+		if (nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX]) {
+			uint64_t max;
+			char max_name[64];
+
+			max = mnl_attr_get_u64(
+				nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX]);
+			snprintf(max_name, sizeof(max_name), "%s-max", name);
+			print_u64(PRINT_JSON, name, NULL, curr);
+			print_u64(PRINT_JSON, max_name, NULL, max);
+			if (!is_json_context()) {
+				char buf[64];
+
+				snprintf(buf, sizeof(buf), "%s %" PRIu64 "/%" PRIu64 " ",
+					 name, curr, max);
+				pr_out("%s", buf);
+			}
+		} else {
+			res_print_u64(name, curr,
+				      nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR]);
+		}
 	}
 	return 0;
 }
diff --git a/rdma/utils.c b/rdma/utils.c
index 87003b2c..90ea1c55 100644
--- a/rdma/utils.c
+++ b/rdma/utils.c
@@ -480,6 +480,7 @@ static const enum mnl_attr_data_type nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
 	[RDMA_NLDEV_ATTR_EVENT_TYPE] = MNL_TYPE_U8,
 	[RDMA_NLDEV_SYS_ATTR_MONITOR_MODE] = MNL_TYPE_U8,
 	[RDMA_NLDEV_ATTR_STAT_OPCOUNTER_ENABLED] = MNL_TYPE_U8,
+	[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX] = MNL_TYPE_U64,
 };
 
 static int rd_attr_check(const struct nlattr *attr, int *typep)
-- 
2.43.0

Re: [PATCH iproute2-next v3] rdma: display resource limits in curr/max format

[David Ahern]

On 6/14/26 6:53 PM, Tao Cui wrote:
> diff --git a/rdma/include/uapi/rdma/rdma_netlink.h b/rdma/include/uapi/rdma/rdma_netlink.h
> index 4356ec4a..e5b8b065 100644
> --- a/rdma/include/uapi/rdma/rdma_netlink.h
> +++ b/rdma/include/uapi/rdma/rdma_netlink.h
> @@ -604,6 +604,11 @@ enum rdma_nldev_attr {
>  	RDMA_NLDEV_ATTR_FRMR_POOL_PINNED_HANDLES,	/* u32 */
>  	RDMA_NLDEV_ATTR_FRMR_POOL_KEY_KERNEL_VENDOR_KEY,	/* u64 */
>  
> +	/*
> +	 * Resource summary entry maximum value.
> +	 */
> +	RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX,		/* u64 */

I do not see this uapi in Linus' tree. What is the status of the kernel
commit? Put a reference to the kernel patches in the commit message.

Re: [PATCH iproute2-next v3] rdma: display resource limits in curr/max format

[Tao Cui]

Hi David,

Thanks for taking a look.

The kernel counterpart that introduces this uapi attribute is the
following patch, currently under review on the rdma list and not yet in
Linus' tree:

  [PATCH rdma-next v3] RDMA/nldev: add resource summary max values for usage display
  https://lore.kernel.org/all/20260615003646.168704-1-cui.tao@linux.dev/

That is the one adding RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX.

You're right that the iproute2 side should reference the kernel patch.
I'll add a Link to it in the commit log of the next revision, e.g.:

  Link: https://lore.kernel.org/all/20260615003646.168704-1-cui.tao@linux.dev/

If you'd prefer, I can also hold this iproute2 patch until the kernel
side has landed, so the uapi is already in tree when it goes in. Happy
to do whichever you think is best.

Thanks,
Tao

在 2026/6/29 01:22, David Ahern 写道:
> On 6/14/26 6:53 PM, Tao Cui wrote:
>> diff --git a/rdma/include/uapi/rdma/rdma_netlink.h b/rdma/include/uapi/rdma/rdma_netlink.h
>> index 4356ec4a..e5b8b065 100644
>> --- a/rdma/include/uapi/rdma/rdma_netlink.h
>> +++ b/rdma/include/uapi/rdma/rdma_netlink.h
>> @@ -604,6 +604,11 @@ enum rdma_nldev_attr {
>>  	RDMA_NLDEV_ATTR_FRMR_POOL_PINNED_HANDLES,	/* u32 */
>>  	RDMA_NLDEV_ATTR_FRMR_POOL_KEY_KERNEL_VENDOR_KEY,	/* u64 */
>>  
>> +	/*
>> +	 * Resource summary entry maximum value.
>> +	 */
>> +	RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX,		/* u64 */
> 
> I do not see this uapi in Linus' tree. What is the status of the kernel
> commit? Put a reference to the kernel patches in the commit message.
>