mlx5dv_devx_subs...ibe_devx_event_fd(3)

💖 NAME 💖

okay bestie, welcome to the mlx5dv_devx_subs...ibe_devx_event_fd(3) manual page — yes, the name is long enough to need a snack break, but the tea is: these functions subscribe over an event channel for device events.

• mlx5dv_devx_subscribe_devx_event — subscribe over an event channel for device events. slay.
• mlx5dv_devx_subscribe_devx_event_fd — subscribe over an event channel for device events to signal eventfd. iconic.

✨ SYNOPSIS ✨

              #include <infiniband/mlx5dv.h>

              int mlx5dv_devx_subscribe_devx_event(struct mlx5dv_devx_event_channel *dv_event_channel,
                                   struct mlx5dv_devx_obj *obj,
                                   uint16_t events_sz,
                                   uint16_t events_num[],
                                   uint64_t cookie)

              int mlx5dv_devx_subscribe_devx_event_fd(struct mlx5dv_devx_event_channel *dv_event_channel,
                                  int fd,
                                  struct mlx5dv_devx_obj *obj,
                                  uint16_t event_num)

🌸 DESCRIPTION 🌸

okay so the whole plot is literally this: subscribe over a DEVX event channel for device events. that's the main character energy of this page. no cap.

🎀 ARGUMENTS 🎀

• dv_event_channel — event channel to subscribe over. that's the channel you're locking in with, bestie 💅
• fd — a file descriptor that previously was opened by the eventfd() system call. so yes, it has already been opened by eventfd() — noted.
• obj — DEVX object that events_num relates to; can be NULL for unaffiliated events. yes, NULL is allowed here for unaffiliated events 🫶
• events_sz — size of the events_num buffer that holds the events to subscribe for. it's giving "buffer size check" energy.
• events_num — holds the required event numbers to subscribe for; numbers are according to the device specification. the device spec is the source of truth here, iykyk.
• cookie — the value to be returned back when reading the event; can be used as an ID for application use. cute little app-side ID moment 🍓

quick bestie note: event_num is chillin' in the mlx5dv_devx_subscribe_devx_event_fd signature up in SYNOPSIS, but the ARGUMENTS list here doesn't give it its own separate description. not me inventing lore 💀

🧚 NOTES 🧚

when mlx5dv_devx_subscribe_devx_event_fd will be used, the fd will be signaled once an event has occurred. that's the whole note, bestie — short, sweet, and signaling. 💖

🦋 SEE ALSO 🦋

• mlx5dv_open_device(3)
• mlx5dv_devx_create_event_channel(3)
• mlx5dv_devx_get_event(3)

👑 AUTHOR 👑

Yishai Hadas <yishaih@mellanox.com>

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