rdtgroup_loc...ser_restrict(9)

✨ NAME ✨

okay so this is the Kernel API Manual page for rdtgroup_locksetup_user_restrict — the header gets chopped down to rdtgroup_loc...ser_restrict(9), which is lowkey tragic but we move. 💅

rdtgroup_locksetup_user_restrict — Restrict user access to group. periodt. 💖

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🌸 SYNOPSIS 🌸

int rdtgroup_locksetup_user_restrict (struct rdtgroup *rdtgrp );

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🎀 ARGUMENTS 🎀

• rdtgrp — resource group needing access restricted. that's the resource group whose access is getting restricted, bestie. 🫶

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💅 DESCRIPTION 💅

okay so here's the tea: a resource group used for cache pseudo-locking cannot have cpus or tasks assigned to it. like, not a single one. 😤

This is communicated to the user by restricting access to all the files that can be used to make such changes — the kernel is basically putting those files behind a velvet rope. 🚧✨

Permissions restored with rdtgroup_locksetup_user_restore — yes, there's a restore bestie for the permissions. 🫶

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🔥 RETURN 🔥

0 on success, <0 on failure. 🎉

If a failure occurs during the restriction of access, an attempt will be made to restore permissions, but the state of the mode of these files will be uncertain when a failure occurs. 😭 so yeah: failure is messy, and the vibe check on those file modes is not guaranteed. 💀

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🦋 SEE ALSO 🦋

Kernel file ./fs/resctrl/pseudo_lock.c is the source file to peek at, and the whole squad is:

• 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_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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mwah 💋 — huge kiss from the ./fs/resctrl source, October 2026 edition. The footer name is still the delightfully chopped rdtgroup_loc...ser_restrict(9), as ever. byeee bestie 🫶✨