ENUM DAMOS_ACTION(9)

💅 enum damos_action(9) — Kernel API Manual 🎀

okay bestie, so this page is from the Kernel API Manual, and it's all about enum damos_action — which, no cap, is the whole menu of moves a DAMOS (that's Data Access Monitoring-based Operation Scheme) can actually pull off. ✨

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🌸 NAME 🌸

enum damos_action — literally represents an action of a Data Access Monitoring-based Operation Scheme. That's it, that's the vibe. 🫶

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🦋 SYNOPSIS 🦋

enum damos_action {
    DAMOS_WILLNEED ,
    DAMOS_COLD ,
    DAMOS_PAGEOUT ,
    DAMOS_HUGEPAGE ,
    DAMOS_NOHUGEPAGE ,
    DAMOS_COLLAPSE ,
    DAMOS_LRU_PRIO ,
    DAMOS_LRU_DEPRIO ,
    DAMOS_MIGRATE_HOT ,
    DAMOS_MIGRATE_COLD ,
    DAMOS_STAT ,
    NR_DAMOS_ACTIONS

};

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⭐ Constants ⭐

okay so here's the whole cast, main character by main character 👑

• DAMOS_WILLNEED — calls madvise on the region with MADV_WILLNEED. she's saying "hey, we're gonna need this soon" 🔮
• DAMOS_COLD — calls madvise on the region with MADV_COLD. marking it as, well… not the moment 🧊
• DAMOS_PAGEOUT — reclaims the region. bye bye bestie 👋
• DAMOS_HUGEPAGE — calls madvise on the region with MADV_HUGEPAGE. big pages energy 🐘
• DAMOS_NOHUGEPAGE — calls madvise on the region with MADV_NOHUGEPAGE. big pages, but make it no 🙅‍♀️
• DAMOS_COLLAPSE — calls madvise on the region with MADV_COLLAPSE. squishing it all together, iconic 🫂
• DAMOS_LRU_PRIO — prioritizes the region on its LRU lists. glow-up, ranking edition 💖
• DAMOS_LRU_DEPRIO — deprioritizes the region on its LRU lists. demoted, but make it fashion 😭
• DAMOS_MIGRATE_HOT — migrates the regions, prioritizing warmer regions. moving the hot girlies first 🔥
• DAMOS_MIGRATE_COLD — migrates the regions, prioritizing colder regions. moving the chill ones first 🌨️
• DAMOS_STAT — does absolutely nothing except count the stat. literally just standing there, observing, taking notes 📊
• NR_DAMOS_ACTIONS — the total number of DAMOS actions. the headcount, the roster size 🧮

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💜 Description 💜

so here's the tea: whether each action is actually supported is entirely up to whichever struct damon_operations is running at the time. it's giving "depends on the group chat you're in." 🫠

if you wanna know the real support status for each one, go check the 'Operation Action' section of Documentation/mm/damon/design.rst — that's the receipts, iykyk. 📚

⚠️ lowkey important: note that DAMOS_PAGEOUT doesn't trigger demotions. not a demotion, no cap. don't @ me.

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🌈 SEE ALSO 🌈

the whole friend group, in the kernel file ./include/linux/damon.h:

• struct damon_addr_range(9)
• struct damon_size_range(9)
• struct damon_region(9)
• struct damon_target(9)
• enum damos_quota_goal_metric(9)
• struct damos_quota_goal(9)
• enum damos_quota_goal_tuner(9)
• struct damos_quota(9)
• enum damos_wmark_metric(9)
• struct damos_watermarks(9)
• struct damos_stat(9)
• enum damos_filter_type(9)
• struct damos_filter(9)
• struct damos_walk_control(9)
• struct damos_access_pattern(9)
• struct damos_migrate_dests(9)
• struct damos(9)
• enum damon_ops_id(9)
• struct damon_operations(9)
• struct damon_intervals_goal(9)
• enum damon_filter_type(9)
• struct damon_filter(9)
• struct damon_probe(9)
• struct damon_attrs(9)
• struct damon_ctx(9)

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and that's the page!! 💅 this little beauty lives in ./include/linux and it's dated October 2026 — so yeah, she's from the future, slay. mwah, go read your structs bestie 🎀✨💖