pseudo_lock...es_constrain(9)

💅 pseudo_lock_cstates_constrain(9) — the kernel API manual, bestie edition 🎀

okay so this is a page straight out of the Kernel API Manual, and it's about keeping your cores out of the deepest sleepy-girl state. literally the whole point. let's get into it 🦋

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✨ NAME ✨

pseudo_lock_cstates_constrain — bestie, this one restricts cores from entering C6 😴🚫

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✨ SYNOPSIS ✨

int pseudo_lock_cstates_constrain (struct pseudo_lock_region *plr );

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✨ ARGUMENTS ✨

• plr — the pseudo-locked region in question. that's your girl 🫶

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✨ DESCRIPTION ✨

so here's the drama 🔥 — to prevent the cache from being affected by power management, entering C6 has to be avoided. like, non-negotiable. and the way we do that is by requesting a latency requirement that's lower than the lowest C6 exit latency of all supported platforms, as found in the cpuidle state tables in the intel_idle driver. and ngl, at this time it's possible to do so with a single latency requirement for all supported platforms. one requirement to rule them all, periodt 👑

but wait, there's more 😭 — since Goldmont is supported, and Goldmont is affected by X86_BUG_MONITOR, the ACPI latencies need to be considered while keeping in mind that C2 may be set to map to deeper sleep states. so in this case the latency requirement needs to prevent entering C2 also. yeah. it's giving "one more thing to worry about" 💀

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✨ RETURN ✨

• 0 on success 💖
• <0 on failure 😭

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✨ SEE ALSO ✨

Kernel file ./fs/resctrl/pseudo_lock.c and all her friends, fr fr:

• pseudo_lock_minor_get(9)
• pseudo_lock_minor_release(9)
• region_find_by_minor(9)
• struct pseudo_lock_pm_req(9)
• pseudo_lock_region_clear(9)
• pseudo_lock_region_init(9)
• pseudo_lock_init(9)
• pseudo_lock_region_alloc(9)
• pseudo_lock_free(9)
• rdtgroup_monitor_in_progress(9)
• rdtgroup_locksetup_user_restrict(9)
• rdtgroup_locksetup_user_restore(9)
• rdtgroup_locksetup_enter(9)
• rdtgroup_locksetup_exit(9)
• rdtgroup_cbm_overlaps_pseudo_locked(9)
• rdtgroup_pseudo_locked_in_hierarchy(9)
• pseudo_lock_measure_cycles(9)
• rdtgroup_pseudo_lock_create(9)
• rdtgroup_pseudo_lock_remove(9)

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okay that's the whole page, you ate that 🍓✨ this gem lives over in ./fs/resctrl, dated October 2026, and it answers to the name pseudo_lock...es_constrain(9). mwah, go keep those cores awake 💜🌈👑