vmw_cmdbuf_alloc(9)

📦 version 7.3.1, in nixpkgs unstable

💅 vmw_cmdbuf_alloc — kernel API manual, but make it make sense

okay bestie, so this is a page from the Kernel API Manual about vmw_cmdbuf_alloc(9), and it's lowkey iconic because it's the "gimme a buffer" function. let's get into it 🎀

✨ NAME ✨

vmw_cmdbuf_alloc — allocate a command buffer header, complete with command buffer space. yes, it does both. overachiever behavior 💅

🦋 SYNOPSIS 🦋

void * vmw_cmdbuf_alloc (struct vmw_cmdbuf_man *man , size_t size , bool
interruptible , struct vmw_cmdbuf_header **p_header );

🌸 ARGUMENTS 🌸

  • man — the command buffer manager. it's literally the main character here 👑
  • size — the requested size of the buffer space. how much room you're asking for, fr fr.
  • interruptible — whether to sleep interruptible while waiting for space. so like, do you wanna be woken up mid-wait or not 😴
  • p_header — points to a header pointer to populate on successful return. it gets filled in for you on the way out, so cute 🫶

💖 DESCRIPTION 💖

so here's the tea: it returns a pointer to command buffer space if it worked. slay. ✨

otherwise? it returns an error pointer. not slay, but honest 💀

and the header pointer it hands back in p_header? that's the one you should use for the upcoming calls to vmw_cmdbuf_reserve and vmw_cmdbuf_commit. don't lose it, bestie. iykyk 🙈

ngl, remember: success = pointer to buffer space. failure = error pointer. the p_header out-param is your ticket for the next two calls.

🔥 SEE ALSO 🔥

the whole friend group, no cap:

and that's the whole page, periodt 💅✨

source/version: ./drivers/gpu/drm/vmwgfx  •  dated October 2026 — shoutout to the driver directory for sponsoring this episode, love u 🫶🎀

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