snd_pcm_lib_malloc_pages(9)

📦 version 7.3.1, in nixpkgs unstable

💖 snd_pcm_lib_malloc_pages(9) 💖

okay bestie, grab your iced coffee 🍓 — welcome to the Kernel API Manual, where we're talking about snd_pcm_lib_malloc_pages, aka the function that literally hands your PCM stream its DMA buffer. it's giving "allocator era" 👑

✨ NAME ✨

snd_pcm_lib_malloc_pages — allocate the DMA buffer 🎀

🦋 SYNOPSIS 🦋

int snd_pcm_lib_malloc_pages (struct snd_pcm_substream *substream ,
size_t size );

like, that's the whole summoning circle. two args, one int back. no cap. ✨

🌸 ARGUMENTS 🌸

  • substream — the substream you're allocating the DMA buffer to. this is the main character of the operation, the one getting the buffer 💅
  • size — the requested buffer size, in bytes. yes, bytes. not pages, not vibes. bytes. 🔥

💜 DESCRIPTION 💜

so here's the tea 🫖: this function allocates the DMA buffer on the BUS type that you already gave earlier to snd_pcm_lib_preallocate_xxx_pages. like, the preallocate call set the vibe, and now snd_pcm_lib_malloc_pages shows up and actually does the allocating. it's a whole two-step choreography, iykyk 🧚

no surprises, no plot twists — it just goes and gets the buffer on the bus type you picked out earlier. slay. 🌈

⭐ RETURN ⭐

bestie, the return value is a whole personality test:

  • 1 — the buffer is changed 🔥 (something happened, we love growth)
  • 0 — the buffer is not changed 😌 (no notes, staying exactly as it was)
  • a negative code — failure 💀 (the buffer said "not today")
fr fr, always check that return value. a negative code is your cue to stop and deal with it, not to pretend you didn't see it 🙈

🎀 SEE ALSO 🎀

Kernel file ./sound/core/pcm_memory.c — go read it, the source is right there 👑

the whole friend group, together at last 🫶

that's the page, bestie 💖 it lives in ./sound/core, it's dated October 2026, and it's page snd_pcm_lib_malloc_pages(9) of the Kernel API Manual — go allocate something iconic ✨👑💅

📦 where this page comes from