dmem_cgroup...mon_ancestor(9)

✨ dmem_cgroup_get_common_ancestor(9) ✨

okay so bestie, we're in the Kernel API Manual today and this one is literally about finding family 💅 no cap, it's a whole ancestry.com situation but for cgroup pools 🧬

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🌸 NAME 🌸

dmem_cgroup_get_common_ancestor — find the first common ancestor of two pools 🫶

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🎀 SYNOPSIS 🎀

struct dmem_cgroup_pool_state * dmem_cgroup_get_common_ancestor (struct
dmem_cgroup_pool_state *a , struct dmem_cgroup_pool_state *b );

like, you hand it two pools and it goes "hmm who's your shared parent bestie" 💖

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🦋 ARGUMENTS 🦋

• a — first pool to find the common ancestor of ✨
• b — first pool to find the common ancestor of.

not me noticing they literally wrote "first" for both 💀 but that is exactly what the page says, so I'm keeping it, iykyk 🙈 think of b as the other pool you're comparing 🍓

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🔥 RETURN 🔥

The first pool that is a parent of both a and b 👑 — or NULL if either a or b are NULL, or if such a pool just... doesn't exist 😭 (some pools are orphans, it's giving tragic).

🚨 okay listen, this part matters fr fr: a reference to the returned pool is grabbed and it must be released by the caller when it's done using the pool. don't just vibe with it forever, that's a leak and we do NOT stan leaks 💀 release it, periodt 🫶

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🌈 SEE ALSO 🌈

Kernel file ./kernel/cgroup/dmem.c — plus the whole squad, go read these too bestie:

• dm_cgroup_state_evict_valuable(9) — wait, the page says dm_cgroup_state_evict_valuable(9), keep it exactly as written ⭐
• dm_cgroup_unregister_region(9)
• dm_cgroup_register_region(9)
• dm_cgroup_pool_state_put(9)
• dm_cgroup_uncharge(9)
• dm_cgroup_try_charge(9)
• dm_cgroup_below_min(9)
• dm_cgroup_below_low(9)

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🌸 💜 🧚 and that's the whole page, bestie — this one lives in ./kernel/cgroup, version vibes from October 2026, mwah 💅✨ go grab that reference and put it back 🫶👑