STRUCT RDT_HW_L3_MON_DOMAIN(9)

🌸 NAME 🌸

okay so bestie, welcome to the Kernel API Manual page for struct rdt_hw_l3_mon_domain(9) — literally the arch-private attributes of a set of CPUs that share RDT_RESOURCE_L3 monitoring. that's the whole vibe. it's the little secret attic where the architecture keeps its own stuff 🎀

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✨ SYNOPSIS ✨

like, here's the shape of it, no cap:

struct rdt_hw_l3_mon_domain {
    struct rdt_l3_mon_domain        d_resctrl;
    struct arch_mbm_state *arch_mbm_states[QOS_NUM_L3_MBM_EVENTS];
};

that's it. that's the struct. she's compact, she's iconic 💅

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🦋 Members 🦋

• d_resctrl — the properties that get exposed to the resctrl file system. this is the extroverted member, the one who actually talks to people 🫶
• arch_mbm_states — a per-event pointer to the MBM event's saved state. and what's an MBM event's state, you ask? it's an array of struct arch_mbm_state indexed by RMID on x86. yes, array-in-a-pointer, indexed by RMID, on x86 specifically. iykyk 😭

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💖 Description 💖

the members of this structure are accessed via helpers that provide abstraction. that's the whole description, bestie — she's a private-attributes girlie and she's not here to be touched directly. use the helpers, respect the abstraction layer, periodt ✨

fr fr do not just go grabbing at these members raw. there are helpers for exactly this. that's the point the page is making, and we listen 👑

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🌈 SEE ALSO 🌈

go read these next, they're all linked in the kernel file ./arch/x86/kernel/cpu/resctrl/internal.h:

• struct arch_mbm_state(9)
• struct rdt_hw_ctrl_domain(9)
• struct rdt_perf_pkg_mon_domain(9)
• struct msr_param(9)
• struct rdt_hw_resource(9)

a whole friend group, honestly. study them together 💜

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and that's the page!! 🎀 snagged from ./arch/x86/kernel/cpu/resctrl, dated October 2026, and yes it's still struct rdt_hw_l3_mon_domain(9) at the bottom — she signs her name every time 🧚‍♀️💖