add_modify_gid(9)

💫 add_modify_gid — a kernel API manual moment 💫

okay so bestie, welcome to the Kernel API Manual, and today's main character is add_modify_gid — the little function that handles adding or modifying a GID table entry. yes that's the whole vibe. let's get into it 🎀

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✨ NAME ✨

add_modify_gid — Add or modify GID table entry 🦋

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🌸 SYNOPSIS 🌸

int add_modify_gid (struct ib_gid_table *table , const struct
       ib_gid_attr *attr );

like. look at her. two params, one int return, absolute icon behavior 💅

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🫶 ARGUMENTS 🫶

• table — the GID table where our GID is gonna get added or modified, iykyk 📋
• attr — the attributes of the GID, aka everything you need to know about her ✨

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💖 DESCRIPTION 💖

so what does she actually do? she returns 0 on success, or an appropriate error code if things go sideways. no cap 😭

she also accepts zero GID addition for non RoCE ports — specifically for HCA's who report them as valid GID. iconic of them honestly.

🚨 but listen: such zero GIDs are not added to the cache. literally not invited to the party. periodt. 💀

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👑 SEE ALSO 👑

bestie you are gonna want the whole friend group, so here's everybody — and yes, they all live in the Kernel file ./drivers/infiniband/core/cache.c:

• free_gid_work(9)
• del_gid(9)
• rdma_find_gid_by_port(9)
• rdma_find_gid_by_filter(9)
• rdma_query_gid(9)
• rdma_read_gid_hw_context(9)
• rdma_find_gid(9)
• rdma_get_gid_attr(9)
• rdma_query_gid_table(9)
• rdma_put_gid_attr(9)
• rdma_hold_gid_attr(9)
• rdma_read_gid_attr_ndev_rcu(9)
• rdma_read_gid_l2_fields(9)
• ib_dispatch_event(9)

the way that's a whole squad 🔥

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🌈 and that's the page! this one came from source/version ./drivers/infiniband/core, dated October 2026 — go drink some water and go touch a GID table, love u, bye 💜🧚