rdtgroup_cbm_overlaps(9)

📦 version 7.3.1, in nixpkgs unstable

💅 rdtgroup_cbm_overlaps(9) 💅

okay bestie, welcome to the rdtgroup_cbm_overlaps page from the Kernel API Manual — yes it's a kernel function, yes it's a whole vibe, and yes we're gonna get through it together 🫶

✨ NAME ✨

rdtgroup_cbm_overlaps — literally just answers the question: does this CBM overlap with some other use of the hardware? 👀

🌸 SYNOPSIS 🌸

bool rdtgroup_cbm_overlaps (struct resctrl_schema *s , struct
rdt_ctrl_domain *d , unsigned long cbm , int closid , bool exclusive );

no cap, that's the whole signature — every type, every comma-that-has-a-space-before-it, all of it, exactly as it lives in the kernel 💖

🎀 ARGUMENTS 🎀

  • s — the schema for the resource that domain instance d belongs to. it's giving "which resource are we even talking about" energy 🌈
  • d — the domain instance we're testing closid against. main character of the overlap test fr fr 👑
  • cbm — the capacity bitmask being tested. that's the mask, bestie, the actual bits 💅
  • closid — the intended closid for cbm. like, where this bitmask wants to live 🦋
  • exclusive — only check if it overlaps with exclusive resource groups. so like, a narrower vibe check 🔥

⭐ DESCRIPTION ⭐

okay so here's the lore 📖

resources that can be allocated using a CBM can use the CBM to control the overlap of those allocations, and rdtgroup_cmb_overlaps is the test for overlap ✨

but wait — the overlap test is not limited to the specific resource that the CBM was intended for, though 😳 when you're dealing with CDP resources that share the underlying hardware, the overlap check should be performed on the CDP resource sharing the hardware also. yep, that's the whole point — check the sibling too, iykyk 💀

for the actual deets of the overlap test, go look at the description of __rdtgroup_cbm_overlaps. it's the source of truth, the blueprint, the og 👑

💜 RETURN 💜

  • true — CBM overlap detected 🚨 not it
  • false — there is no overlap 💚 we love a clean slate

🌈 SEE ALSO 🌈

kernel file ./fs/resctrl/rdtgroup.c — that's the home base bestie 🏠

and the whole friend group:

aaaaand that's the page 💅 this one's sourced from ./fs/resctrl, version-dated October 2026, and it slayed the whole way through. periodt 🎀✨🦋

📦 where this page comes from