io_subchannel_sch_event(9)

📦 version 7.3.1, in nixpkgs unstable

💅 io_subchannel_sch_event 💅

okay so this is a page from the Kernel API Manual — yeah, the big serious kernel docs — and we're about to make it make sense. it's giving "s390 cio core" energy, and honestly? iconic. let's go 🫶

✨ NAME ✨

io_subchannel_sch_event — literally just process subchannel event. that's the whole vibe. it handles a subchannel event. no cap.

🦋 SYNOPSIS 🦋

int io_subchannel_sch_event (struct subchannel *sch , int process );

look at her. two args, one int coming back at you. main character function fr fr 💜

🎀 ARGUMENTS 🎀

  • sch — the subchannel. that's it, that's the whole description. she's a struct subchannel * and she's the one we're event-ing on 💅
  • process — non-zero if this function is called in process context. so like, if you're running in process context, pass something non-zero, bestie. zero means you're not 👑

🔥 DESCRIPTION 🔥

so picture this: an event happened on this subchannel. and not just any event — an unspecified one 😭 the docs literally do not say which. mysterious. slay.

what you do is adjust the data according to the current operational state of the subchannel and the device. like, read the room first, then react. vibe check the subchannel, vibe check the device, then update accordingly ✨

the return value is where it gets good:

  • return zero when the event has been handled sufficiently — like, you're done, you ate, periodt 👑
  • return -EAGAIN when this function should be called again in process context — iykyk, it's the "run it back" signal 🌀

so basically: handle it, or tell the caller to come back later with process context. no in-between. 🌸

🌈 SEE ALSO 🌈

the kernel file lives at ./drivers/s390/cio/device.c (yes, that's the actual path, don't come for me 🫶) and these are her friends, her little crew, her mutuals:

go read those too, bestie, they're all in the same little ./drivers/s390/cio friend group 💖

ok that's the whole page!! sourced from the ./drivers/s390/cio directory, October 2026 vintage — she's fresh, she's documented, and io_subchannel_sch_event(9) is her name. mwah 💋 🎀
📦 where this page comes from