rdma_cap_ib_cm(9)

🌸 rdma_cap_ib_cm 💅

okay so this is the rdma_cap_ib_cm page from the Kernel API Manual, section 9 — yes, section 9, the kernel-API girlies. sit down bestie, this one's short and sweet and it's literally just a capability check. 🎀

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✨ NAME ✨

rdma_cap_ib_cm — checks whether the port on your device has the Infiniband Communication Manager capability. that's it. that's the whole vibe check. 🦋

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✨ SYNOPSIS ✨

bool rdma_cap_ib_cm (const struct ib_device *device , u32 port_num );

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✨ ARGUMENTS ✨

• device — the device you wanna check, bestie. that's the one.
• port_num — the port number you're checking on it. yes, port-specific, don't @ me.

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✨ DESCRIPTION ✨

okay so picture this: the InfiniBand Communication Manager is one of many pre-defined General Service Agents (GSA for short, iykyk) that you get to through the General Service Interface (GSI). it's giving highly organized.

and what does it actually do? its whole role is to facilitate establishment of connections between nodes 💖 — plus other management related tasks for connections that are already established. so it's the social butterfly of the fabric, lowkey. makes the intros, keeps the group chat alive. 🫶

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✨ RETURN ✨

true if the port supports an IB CM. 🎉

⚠️ important caveat, bestie, don't skip this: true does not guarantee that a CM is actually running however. it just means the port supports it. capability ≠ currently-on. two totally different things. 💀

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✨ SEE ALSO ✨

so many friends, so many cross-references, all of them exactly as they are, no cap:

• Kernel file ./include/rdma/ib_verbs.h
• struct rdma_stat_desc(9), struct rdma_hw_stats(9), ib_rate_to_mult(9), ib_rate_to_mbps(9)
• ib_port_attr_to_speed_info(9), enum ib_mr_type(9), struct ib_mr_status(9), mult_to_ib_rate(9)
• struct ib_udata(9), struct rdma_netdev(9), struct ib_device_ops(9), ib_get_client_data(9)
• ib_modify_qp_is_ok(9), rdma_cap_ib_switch(9), rdma_start_port(9), rdma_for_each_port(9)
• rdma_end_port(9), rdma_cap_ib_mad(9), rdma_cap_opa_mad(9), rdma_cap_ib_smi(9)
• rdma_cap_iw_cm(9), rdma_cap_ib_sa(9), rdma_cap_ib_mcast(9), rdma_cap_af_ib(9)
• rdma_cap_eth_ah(9), rdma_cap_opa_ah(9), rdma_max_mad_size(9), rdma_cap_roce_gid_table(9)
• rdma_core_cap_opa_port(9), rdma_mtu_enum_to_int(9), rdma_mtu_from_attr(9), ib_alloc_pd(9)
• ib_dealloc_pd(9), rdma_create_ah(9), rdma_create_user_ah(9), ib_get_gids_from_rdma_hdr(9)
• ib_get_rdma_header_version(9), ib_init_ah_attr_from_wc(9), ib_create_ah_from_wc(9), rdma_modify_ah(9)
• rdma_query_ah(9), rdma_destroy_ah_user(9), rdma_destroy_ah(9), ib_modify_srq(9)
• ib_query_srq(9), ib_destroy_srq_user(9), ib_destroy_srq(9), ib_post_srq_recv(9)
• ib_create_qp(9), ib_modify_qp_with_udata(9), ib_modify_qp(9), ib_query_qp(9)
• ib_destroy_qp(9), ib_open_qp(9), ib_close_qp(9), ib_post_send(9)
• ib_post_recv(9), ib_alloc_cq_any(9), rdma_set_cq_moderation(9), ib_destroy_cq_user(9)
• ib_destroy_cq(9), ib_poll_cq(9), ib_req_notify_cq(9), ib_virt_dma_to_ptr(9)
• ib_virt_dma_to_page(9), ib_dma_mapping_error(9), ib_dma_map_single(9), ib_dma_unmap_single(9)
• ib_dma_map_page(9), ib_dma_unmap_page(9), ib_dma_map_bvec(9), ib_dma_unmap_bvec(9)
• ib_dma_map_sgtable_attrs(9), ib_dma_map_sg(9), ib_dma_unmap_sg(9), ib_dma_max_seg_size(9)
• ib_dma_sync_single_for_cpu(9), ib_dma_sync_single_for_device(9), ib_dereg_mr_user(9), ib_dereg_mr(9)
• ib_update_fast_reg_key(9), ib_inc_rkey(9), ib_attach_mcast(9), ib_detach_mcast(9)
• ib_check_mr_status(9), ib_device_try_get(9), rdma_ah_find_type(9), ib_lid_cpu16(9)
• ib_lid_be16(9), rdma_roce_rescan_device(9), rdma_device_to_ibdev(9), ibdev_to_node(9)
• rdma_device_to_drv_device(9), rdma_flow_label_to_udp_sport(9), rdma_calc_flow_label(9), rdma_get_udp_sport(9)

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and that's the page!! 🧚 this gorgeous lil number comes to you courtesy of the source path ./include/rdma, dated October 2026 — so mark your calendars, bestie, because that's the version and date slay we're all stanning. 👑💜 stay hydrated, read your man pages, periodt. 💖