STRUCT CACHEINFO(9)

🌸 NAME

struct cacheinfo — represent a cache leaf node. Okay bestie, this is struct cacheinfo(9) straight out of the Kernel API Manual, and it's giving very specific kernel-cache energy 💅✨

✨ SYNOPSIS

       struct cacheinfo {
           unsigned int id;
           enum cache_type type;
           unsigned int level;
           unsigned int coherency_line_size;
           unsigned int number_of_sets;
           unsigned int ways_of_associativity;
           unsigned int physical_line_partition;
           unsigned int size;
           cpumask_t shared_cpu_map;
           unsigned int attributes;
         #define CACHE_WRITE_THROUGH     BIT(0);
         #define CACHE_WRITE_BACK        BIT(1);
         #define CACHE_WRITE_POLICY_MASK                 (CACHE_WRITE_THROUGH |
       CACHE_WRITE_BACK);
         #define CACHE_READ_ALLOCATE     BIT(2);
         #define CACHE_WRITE_ALLOCATE    BIT(3);
         #define CACHE_ALLOCATE_POLICY_MASK              (CACHE_READ_ALLOCATE |
       CACHE_WRITE_ALLOCATE);
         #define CACHE_ID                BIT(4);
           void *fw_token;
           bool disable_sysfs;
           void *priv;
        };

💅 Members

• id — this cache's id. It is unique among caches with the same (type, level). No duplicates in that little squad, periodt 💖
• type — type of the cache: data, inst, or unified. Pick your fighter ✨
• level — represents the hierarchy in the multi-level cache. It's giving cache-floor realness 🏢
• coherency_line_size — size of each cache line, usually representing the minimum amount of data that gets transferred from memory. Iconic little transfer unit 🎀
• number_of_sets — total number of sets; a set is a collection of cache lines sharing the same index. Set theory but make it cache 🧚
• ways_of_associativity — number of ways in which a particular memory block can be placed in the cache. So many options, honestly 🦋
• physical_line_partition — number of physical cache lines sharing the same cachetag. Shared tag moment 😭
• size — total size of the cache. Big? Small? It's in there 💀
• shared_cpu_map — logical cpumask representing all the cpus sharing this cache node. CPU besties sharing one cache 🫶
• attributes — bitfield representing various cache attributes. The CACHE_* defines up top are living here, iykyk 🔥
• fw_token — unique value used to determine if different cacheinfo structures represent a single hardware cache instance. One hardware cache, one token, no cap 👑
• disable_sysfs — indicates whether this node is visible to the user via sysfs or not. Visible or lowkey hidden 🙈
• priv — pointer to any private data structure specific to particular cache design. Private data stays private, bestie 💜

🦋 Description

While of_node, disable_sysfs, and priv are used for internal book keeping, the remaining members form the core properties of the cache. That's the whole vibe check 🌈

👑 SEE ALSO

• Kernel file ./include/linux/cacheinfo.h — go read it, bestie 📖

source/version: ./include/linux • date: October 2026 • page: struct cacheinfo(9) — mwah 💋 bye bestie 🫶