STRUCT DAMON_REGION(9)

💖 struct damon_region(9) 💖

okay so bestie, this is the Kernel API Manual page for struct damon_region — the little struct that represents a monitoring target region, and honestly? iconic. ✨

🌸 NAME 🌸

struct damon_region — Represents a monitoring target region. 🎀

🦋 SYNOPSIS 🦋

       struct damon_region {
           struct damon_addr_range ar;
           unsigned long sampling_addr;
           unsigned int nr_accesses;
           unsigned char probe_hits[DAMON_MAX_PROBES];
           unsigned int age;
        };

🌟 Members 🌟

• ar — The address range of the region. 🗺️
• sampling_addr — Address of the sample for the next access check. 👀
• nr_accesses — Access frequency of this region. 🔥
• probe_hits — Number of probe-positive region samples. 🎯
• age — Age of this region. 🕰️

💅 Description 💅

For any use case, ar should be non-zero positive size. damon_set_regions does the validation — so let it handle the check, okay? 🫶

nr_accesses is reset to zero for every damon_attrs->aggr_interval, and it is increased for every damon_attrs->sample_interval if an access to the region during the last sampling interval is found. The update of this field should not be done with direct access but with the helper function, damon_update_region_access_rate. 🚨

bestie do NOT touch nr_accesses directly — use the helper damon_update_region_access_rate. that's the rule. periodt. 💅

age is initially zero, increased for each aggregation interval, and reset to zero again if the access frequency is significantly changed. If two regions are merged into a new region, both nr_accesses and age of the new region are set as region size-weighted average of those of the two regions. 🌀

🔥 SEE ALSO 🔥

go peek at the kernel file ./include/linux/damon.h and these pages bestie:

• struct damon_addr_range(9)
• struct damon_size_range(9)
• struct damon_target(9)
• enum damos_action(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)

mwah 💋 this page comes from ./include/linux, dated October 2026, and it's all struct damon_region(9) — bye bestie 🫶🌈