rdtgroup_locksetup_enter(9)

💅 rdtgroup_locksetup_enter(9) 💅

okay so bestie, welcome to the Kernel API Manual ✨ today’s main character is rdtgroup_locksetup_enter, and it’s all about getting a resource group into locksetup mode. no cap, this is very much “we’re setting up a pseudo-locked region, pls respect the process” energy 🦋

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🌸 NAME 🌸

rdtgroup_locksetup_enter — Resource group enters locksetup mode 💖

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✨ SYNOPSIS ✨

int rdtgroup_locksetup_enter (struct rdtgroup *rdtgrp );

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🎀 ARGUMENTS 🎀

• rdtgrp — the resource group requested to enter locksetup mode. that’s the one asking for the locksetup glow-up ✨

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💖 DESCRIPTION 💖

so here’s the tea 🫖 A resource group enters locksetup mode to reflect that it would be used to represent a pseudo-locked region and is in the process of being set up to do so.

A resource group used for a pseudo-locked region would lose the closid associated with it, so we cannot allow it to have any tasks or cpus assigned, nor permit tasks or cpus to be assigned in the future. Monitoring of a pseudo-locked region is not allowed either 🚫👀

The above and more restrictions on a pseudo-locked region are checked for and enforced before the resource group enters the locksetup mode. like, the vibe check happens first, periodt 💅

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🔥 RETURN 🔥

• 0 if the resource group successfully entered locksetup mode ✅
• <0 on failure 😭

On failure the last_cmd_status buffer is updated with text to communicate details of failure to the user. very “here’s what went wrong, bestie” of it 💌

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👑 SEE ALSO 👑

Kernel file: ./fs/resctrl/pseudo_lock.c 📁

• pseudo_lock_minor_get(9)
• pseudo_lock_minor_release(9)
• region_find_by_minor(9)
• struct pseudo_lock_pm_req(9)
• pseudo_lock_cstates_constrain(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_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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from the source at ./fs/resctrl, dated October 2026 — bye bestie, go forth and locksetup responsibly 💖🎀