mbox_chan_tx...ts_available(9)

📦 version 7.3.1, in nixpkgs unstable

💌 mbox_chan_tx_slots_available(9) 💌

okay bestie, welcome to the Kernel API Manual — this is the page for mbox_chan_tx_slots_available, and yes we're gonna make mailbox queues make sense together 🫶

✨ NAME ✨

mbox_chan_tx_slots_available — literally just tells you how many free TX queue slots you've got left, no cap 💅

🌸 SYNOPSIS 🌸

unsigned int mbox_chan_tx_slots_available (struct mbox_chan *chan );

🎀 ARGUMENTS 🎀

  • chan — the mailbox channel you're snooping on, iykyk. That's the one you're querying 🦋

💖 DESCRIPTION 💖

So here's the vibe: clients can call this to check how many messages they can still queue up via mbox_send_message before the channel's TX queue is, like, completely full 😭

It's giving preventative self-care — this is how you dodge the -ENOBUFS error without having to go increase MBOX_TX_QUEUE_LEN. iconic behavior honestly 👑

And the best part? This can be called from atomic context. slay ✨

🔥 RETURN 🔥

The number of available slots in the channel's TX queue. that's it, that's the tea 🍓

🌈 SEE ALSO 🌈

Kernel file ./drivers/mailbox/mailbox.c — and the whole friend group:

ngl, if you're about to hit a full queue and you skip this check, that's on you bestie 💀

okay that's the whole page!! it lives in ./drivers/mailbox, the version vibes are from October 2026, and the page signature at the bottom is mbox_chan_tx...ts_available(9) — go forth and queue responsibly, mwah 🧚💜

📦 where this page comes from