Subject: Re: [PATCH RFC iproute-next 3/5] rdma: Add CQ resource tracking information

From: Leon Romanovsky <[email-masked]>
Date: Tue, 20 Feb 2018 15:09:16 +0200

On Wed, Feb 14, 2018 at 01:07:01PM -0800, Steve Wise wrote:
> Sample output:
>
> # rdma resource show cq
> link cxgb4_0/- cqe 46 usecnt 2 pid 30503 comm rping
> link cxgb4_0/- cqe 46 usecnt 2 pid 30498 comm rping
> link mlx4_0/- cqe 63 usecnt 2 pid 30494 comm rping
> link mlx4_0/- cqe 63 usecnt 2 pid 30489 comm rping
> link mlx4_0/- cqe 1023 usecnt 2 poll_ctx WORKQUEUE pid 0 comm [ib_core]
>
> # rdma resource show cq pid 30489
> link mlx4_0/- cqe 63 usecnt 2 pid 30489 comm rping
>
> Signed-off-by: Steve Wise <[email-masked]>
> ---
>  rdma/res.c   | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  rdma/utils.c |   5 +++
>  2 files changed, 128 insertions(+)
>
> diff --git a/rdma/res.c b/rdma/res.c
> index beae7dc..27c1efd 100644
> --- a/rdma/res.c
> +++ b/rdma/res.c
> @@ -21,6 +21,8 @@ static int res_help(struct rd *rd)
>  	pr_out("          resource show qp link [DEV/PORT] [FILTER-NAME FILTER-VALUE]\n");
>  	pr_out("          resource show cm_id link [DEV/PORT]\n");
>  	pr_out("          resource show cm_id link [DEV/PORT] [FILTER-NAME FILTER-VALUE]\n");
> +	pr_out("          resource show cq link [DEV/PORT]\n");
> +	pr_out("          resource show cq link [DEV/PORT] [FILTER-NAME FILTER-VALUE]\n");
>  	return 0;
>  }
>
> @@ -705,6 +707,118 @@ static int res_cm_id_parse_cb(const struct nlmsghdr *nlh, void *data)
>  	return MNL_CB_OK;
>  }
>
> +static void print_cqe(struct rd *rd, uint32_t val)
> +{
> +	if (rd->json_output)
> +		jsonw_uint_field(rd->jw, "cqe", val);
> +	else
> +		pr_out("cqe %u ", val);
> +}
> +
> +static void print_usecnt(struct rd *rd, uint64_t val)
> +{
> +	if (rd->json_output)
> +		jsonw_uint_field(rd->jw, "usecnt", val);
> +	else
> +		pr_out("usecnt %" PRIu64 " ", val);

Interesting, how many users are actually know what the "usecnt" actually means?
Will it be more clear to call it "users" instead of "usecnt"?

> +}
> +
> +static const char *poll_ctx_to_str(uint8_t idx)
> +{
> +	static const char * const cm_id_states_str[] = { "DIRECT", "SOFTIRQ",
> +						      "WORKQUEUE"};
> +
> +	if (idx < ARRAY_SIZE(cm_id_states_str))
> +		return cm_id_states_str[idx];
> +	return "UNKNOWN";
> +}
> +
> +static void print_poll_ctx(struct rd *rd, uint8_t poll_ctx)
> +{
> +	if (rd->json_output) {
> +		jsonw_string_field(rd->jw, "poll_ctx", poll_ctx_to_str(poll_ctx));
> +		return;
> +	}
> +	pr_out("poll_ctx %s ", poll_ctx_to_str(poll_ctx));
> +}
> +
> +static int res_cq_parse_cb(const struct nlmsghdr *nlh, void *data)
> +{
> +	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX] = {};
> +	struct nlattr *nla_table, *nla_entry;
> +	struct rd *rd = data;
> +	const char *name;
> +	uint32_t idx;
> +
> +	mnl_attr_parse(nlh, 0, rd_attr_cb, tb);
> +	if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] ||
> +	    !tb[RDMA_NLDEV_ATTR_DEV_NAME] ||
> +	    !tb[RDMA_NLDEV_ATTR_RES_CQ])
> +		return MNL_CB_ERROR;
> +
> +	name = mnl_attr_get_str(tb[RDMA_NLDEV_ATTR_DEV_NAME]);
> +	idx =  mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
> +	nla_table = tb[RDMA_NLDEV_ATTR_RES_CQ];
> +
> +	mnl_attr_for_each_nested(nla_entry, nla_table) {
> +		struct nlattr *nla_line[RDMA_NLDEV_ATTR_MAX] = {};
> +		char *comm = NULL;
> +		uint32_t pid = 0;
> +		uint8_t poll_ctx = 0;
> +		uint64_t usecnt;
> +		uint32_t cqe;
> +		int err;
> +
> +		err = mnl_attr_parse_nested(nla_entry, rd_attr_cb, nla_line);
> +		if (err != MNL_CB_OK)
> +			return MNL_CB_ERROR;
> +
> +		if (!nla_line[RDMA_NLDEV_ATTR_RES_CQE] ||
> +		    !nla_line[RDMA_NLDEV_ATTR_RES_USECNT] ||

I'm not sure that we will have USECNT in the future, let's not put
requirement for RDMA_NLDEV_ATTR_RES_USECNT here.

> +		    (!nla_line[RDMA_NLDEV_ATTR_RES_PID] &&
> +		     !nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME])) {
> +			return MNL_CB_ERROR;
> +		}
> +
> +		cqe = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_CQE]);
> +		usecnt = mnl_attr_get_u64(nla_line[RDMA_NLDEV_ATTR_RES_USECNT]);
> +		if (nla_line[RDMA_NLDEV_ATTR_RES_POLL_CTX])
> +			poll_ctx = mnl_attr_get_u8(nla_line[RDMA_NLDEV_ATTR_RES_POLL_CTX]);
> +
> +		if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) {
> +			pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]);
> +			comm = get_task_name(pid);
> +		}
> +
> +		if (rd_check_is_filtered(rd, "pid", pid))

free(comm);

> +			continue;
> +
> +		if (nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME])
> +			/* discard const from mnl_attr_get_str */
> +			comm = (char *)mnl_attr_get_str(nla_line[RDMA_NLDEV_ATTR_RES_KERN_NAME]);
> +
> +		if (rd->json_output)
> +			jsonw_start_array(rd->jw);
> +
> +		print_link(rd, idx, name, 0, nla_line);
> +		print_cqe(rd, cqe);
> +		print_usecnt(rd, usecnt);
> +		if (nla_line[RDMA_NLDEV_ATTR_RES_POLL_CTX])
> +			print_poll_ctx(rd, poll_ctx);
> +		print_pid(rd, pid);
> +		print_comm(rd, comm, nla_line);
> +
> +		if (nla_line[RDMA_NLDEV_ATTR_RES_PID])
> +			free(comm);
> +
> +		if (rd->json_output)
> +			jsonw_end_array(rd->jw);
> +		else
> +			pr_out("\n");
> +	}
> +	return MNL_CB_OK;
> +}
> +
>  RES_FUNC(res_no_args,	RDMA_NLDEV_CMD_RES_GET,	NULL, true);
>
>  static const struct
> @@ -758,12 +872,21 @@ filters cm_id_valid_filters[MAX_NUMBER_OF_FILTERS] = {{ .name = "link",
>  RES_FUNC(res_cm_id,	RDMA_NLDEV_CMD_RES_CM_ID_GET, cm_id_valid_filters,
>  	 false);
>
> +static const struct
> +filters cq_valid_filters[MAX_NUMBER_OF_FILTERS] = {{ .name = "link",
> +						   .is_number = false },
> +						   { .name = "pid",
> +						   .is_number = true }};

Can you please add filter of usecnt too? It will give us easy view on
"over crowded" CQs.

> +
> +RES_FUNC(res_cq,	RDMA_NLDEV_CMD_RES_CQ_GET, cq_valid_filters, true);
> +
>  static int res_show(struct rd *rd)
>  {
>  	const struct rd_cmd cmds[] = {
>  		{ NULL,		res_no_args	},
>  		{ "qp",		res_qp		},
>  		{ "cm_id",	res_cm_id	},
> +		{ "cq",		res_cq		},
>  		{ 0 }
>  	};
>
> diff --git a/rdma/utils.c b/rdma/utils.c
> index 906ca73..11b34fe 100644
> --- a/rdma/utils.c
> +++ b/rdma/utils.c
> @@ -387,6 +387,11 @@ static const enum mnl_attr_data_type nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
>  	[RDMA_NLDEV_ATTR_RES_DEV_TYPE]		= MNL_TYPE_U8,
>  	[RDMA_NLDEV_ATTR_RES_TRANSPORT_TYPE]	= MNL_TYPE_U8,
>  	[RDMA_NLDEV_ATTR_RES_NETWORK_TYPE]	= MNL_TYPE_U8,
> +	[RDMA_NLDEV_ATTR_RES_CQ] = MNL_TYPE_NESTED,
> +	[RDMA_NLDEV_ATTR_RES_CQ_ENTRY] = MNL_TYPE_NESTED,
> +	[RDMA_NLDEV_ATTR_RES_CQE] = MNL_TYPE_U32,
> +	[RDMA_NLDEV_ATTR_RES_USECNT] = MNL_TYPE_U64,
> +	[RDMA_NLDEV_ATTR_RES_POLL_CTX] = MNL_TYPE_U8,
>  };
>
>  int rd_attr_cb(const struct nlattr *attr, void *data)
> --
> 1.8.3.1
>