folio_lruvec_lock(9)

💅 folio_lruvec_lock(9) — like, the kernel API manual, bestie

okay so here's the tea: this is the man page for folio_lruvec_lock, straight out of the Kernel API Manual. Sit down, grab a boba, we're locking lruvecs 🫶

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✨ NAME ✨

folio_lruvec_lock — locks the lruvec for a folio. that's it, that's the whole vibe 💅

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🌸 SYNOPSIS 🌸

struct lruvec * folio_lruvec_lock (struct folio *folio );

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🎀 ARGUMENTS 🎀

• folio — a pointer to the folio. just a pointer. pointing at a folio. iconic behavior honestly 👑

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💖 DESCRIPTION 💖

so these functions are safe to use under any of the following conditions, no cap:

• folio locked 🔒
• folio_test_lru is false
• folio frozen (refcount of 0) 🧊

like, those are your green lights. if you're chilling in any one of those situations, you're good 😌

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🦋 RETURN 🦋

returns the lruvec this folio is on — with its lock held and the rcu read lock held too. two locks, one return value, main character energy fr fr ✨

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🌈 SEE ALSO 🌈

the kernel file lives at ./mm/memcontrol.c, and it's friends with literally everybody:

• get_mem_cgroup_css_from_folio(9)
• page_cgroup_ino(9)
• lruvec_page_state_monotonic(9)
• mod_memcg_state(9)
• mod_lruvec_state(9)
• count_memcg_events(9)
• get_mem_cgroup_from_mm(9)
• get_mem_cgroup_from_current(9)
• get_mem_cgroup_from_folio(9)
• mem_cgroup_iter(9)
• mem_cgroup_iter_break(9)
• mem_cgroup_scan_tasks(9)
• folio_lruvec_lock_irq(9)
• folio_lruvec_lock_irqsave(9)
• mem_cgroup_update_lru_size(9)
• mem_cgroup_margin(9)
• mem_cgroup_print_oom_context(9)
• mem_cgroup_print_oom_meminfo(9)
• mem_cgroup_get_oom_group(9)
• consume_stock(9)
• __memcg_kmem_charge_page(9)
• __memcg_kmem_uncharge_page(9)
• mem_cgroup_wb_stats(9)
• mem_cgroup_from_private_id(9)
• mem_cgroup_css_reset(9)
• mem_cgroup_calculate_protection(9)
• mem_cgroup_charge_hugetlb(9)
• mem_cgroup_swapin_charge_folio(9)
• mem_cgroup_replace_folio(9)
• mem_cgroup_migrate(9)
• mem_cgroup_sk_charge(9)
• mem_cgroup_sk_uncharge(9)
• __mem_cgroup_try_charge_swap(9)
• __mem_cgroup_uncharge_swap(9)
• obj_cgroup_may_zswap(9)
• obj_cgroup_charge_zswap(9)
• obj_cgroup_uncharge_zswap(9)

like, that's a whole group chat right there 😭

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okay that's the page!! it's from ./mm, dated October 2026, and yeah — that's the whole folio_lruvec_lock(9) situation. go forth and lock responsibly, bestie 💜🧚