DECLARE_KFIFO(9)

✨ DECLARE_KFIFO ✨

okay so bestie, welcome to the Kernel API Manual 💖 this one's a little macro that literally just declares a fifo object for you, no cap. Think of it as the birth certificate of your fifo 🎀

🌸 NAME 🌸

DECLARE_KFIFO — macro to declare a fifo object 💅

🦋 SYNOPSIS 🦋

DECLARE_KFIFO (fifo , type , size );

🎀 ARGUMENTS 🎀

• fifo — the name of the declared fifo. this is what you're gonna call your baby 💖 pick something cute, or y'know, something descriptive, we don't judge.
• type — the type of the fifo elements. like, what are you actually storing in here?? that's this. ✨
• size — the number of elements in the fifo. and this must be a power of 2 👑 no exceptions, non-negotiable, do not come at me with your 3 or your 100, it's giving undefined behaviour energy and we don't do that here 🙈

not me emphasizing this again — size has to be a power of 2, fr fr. that's the whole vibe check for this argument. 🔥

💜 SEE ALSO 💜

• the kernel file ./include/linux/kfifo.h — go read it, it's iconic 🧚
• DECLARE_KFIFO_PTR(9)
• INIT_KFIFO(9)
• DEFINE_KFIFO(9)
• kfifo_initialized(9)
• kfifo_esize(9)
• kfifo_recsize(9)
• kfifo_size(9)
• kfifo_reset(9)
• kfifo_reset_out(9)
• kfifo_len(9)
• kfifo_is_empty(9)
• kfifo_is_empty_spinlocked(9)
• kfifo_is_empty_spinlocked_noirqsave(9)
• kfifo_is_full(9)
• kfifo_avail(9)
• kfifo_skip_count(9)
• kfifo_skip(9)
• kfifo_peek_len(9)
• kfifo_alloc(9)
• kfifo_alloc_node(9)
• kfifo_free(9)
• kfifo_init(9)
• kfifo_put(9)
• kfifo_get(9)
• kfifo_peek(9)
• kfifo_in(9)
• kfifo_in_spinlocked(9)
• kfifo_in_spinlocked_noirqsave(9)
• kfifo_out(9)
• kfifo_out_spinlocked(9)
• kfifo_out_spinlocked_noirqsave(9)
• kfifo_from_user(9)
• kfifo_to_user(9)
• kfifo_dma_in_prepare_mapped(9)
• kfifo_dma_in_finish(9)
• kfifo_dma_out_prepare_mapped(9)
• kfifo_dma_out_finish(9)
• kfifo_out_peek(9)
• kfifo_out_linear(9)
• kfifo_out_linear_ptr(9)

that's a lot of siblings but they all slay in their own way, go check 'em out 🫶

mwah 💋 that's the page! this one lives in ./include/linux in the Kernel API Manual, and it was dated October 2026 — so like, technically from the future, main character energy fr ⭐ bye bestie, go declare some fifos ✨