is_ctrl_pkt(9)

💅 is_ctrl_pkt(9) — the kernel API manual, bestie edition 🎀

okay so you found your way into is_ctrl_pkt(9) — the section 9 kernel API manual page. welcome, pull up a chair, this one's short and sweet and honestly kind of iconic for how much it does with so little ✨

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✨ NAME ✨

is_ctrl_pkt — returns whether an offload packet is a control packet 🦋

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🌸 SYNOPSIS 🌸

unsigned int is_ctrl_pkt (const struct sk_buff *skb );

like, that's the whole signature. one arg. no cap. 💅

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🎀 ARGUMENTS 🎀

• skb — the packet. that's it, that's the description. she's the packet in question, the main character of this whole function, the thing we're vibe-checking 🌈

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👑 DESCRIPTION 👑

so here's the tea ☕ — this function returns whether an offload packet should use an OFLD or a CTRL Tx queue, and the answer lives in bit 0 of the packet's queue_mapping. that's the whole bit. one bit decides which queue your offload packet goes to, and is_ctrl_pkt is the bestie who reads it for you and reports back. literally that simple, fr fr 🫶

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🔥 SEE ALSO 🔥

bestie, get comfy, this list is LONG and we're not skipping a single one, i refuse 😭 this is the whole ./drivers/net/ethernet/chelsio/cxgb4/sge.c kernel file squad:

• txq_avail(9)
• fl_cap(9)
• fl_starving(9)
• deferred_unmap_destructor(9)
• free_tx_desc(9)
• reclaim_completed_tx(9)
• cxgb4_reclaim_completed_tx(9)
• free_rx_bufs(9)
• unmap_rx_buf(9)
• refill_fl(9)
• alloc_ring(9)
• sgl_len(9)
• flits_to_desc(9)
• is_eth_imm(9)
• calc_tx_flits(9)
• cxgb4_write_sgl(9)
• cxgb4_ring_tx_db(9)
• cxgb4_inline_tx_skb(9)
• t4_sge_eth_txq_egress_update(9)
• cxgb4_eth_xmit(9)
• t4vf_is_eth_imm(9)
• t4vf_calc_tx_flits(9)
• cxgb4_vf_eth_xmit(9)
• reclaim_completed_tx_imm(9)
• cxgb4_ethofld_send_flowc(9)
• is_imm(9)
• ctrlq_check_stop(9)
• ctrl_xmit(9)
• restart_ctrlq(9)
• t4_mgmt_tx(9)
• is_ofld_imm(9)
• calc_tx_flits_ofld(9)
• txq_stop_maperr(9)
• ofldtxq_stop(9)
• service_ofldq(9)
• ofld_xmit(9)
• restart_ofldq(9)
• skb_txq(9)
• t4_ofld_send(9)
• cxgb4_ofld_send(9)
• ofld_xmit_direct(9)
• t4_crypto_send(9)
• cxgb4_crypto_send(9)
• cxgb4_pktgl_to_skb(9)
• t4_pktgl_free(9)
• cxgb4_sgetim_to_hwtstamp(9)
• t4_systim_to_hwstamp(9)
• t4_rx_hststamp(9)
• t4_tx_hststamp(9)
• t4_tx_completion_handler(9)
• t4_ethrx_handler(9)
• restore_rx_bufs(9)
• is_new_response(9)
• rspq_next(9)
• process_responses(9)
• napi_rx_handler(9)
• t4_intr_handler(9)
• bar2_address(9)
• t4_sge_alloc_eth_txq(9)
• t4_free_sge_resources(9)
• t4_sge_stop(9)
• t4_sge_init_soft(9)
• t4_sge_init(9)

all 66 of them, accounted for, not one dropped 💖 go read them, i'll wait 🧚

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little sign-off moment 🫶 this page came from ./drivers/net/ethernet/chelsio... and it's dated October 2026, and it's living in the is_ctrl_pkt(9) chapter of your kernel API manual forever. slay. periodt. ⭐💜