diff options
Diffstat (limited to 'include/linux/shrinker.h')
| -rw-r--r-- | include/linux/shrinker.h | 87 |
1 files changed, 55 insertions, 32 deletions
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 224293b2dd06..1a00be90d93a 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -4,6 +4,25 @@ #include <linux/atomic.h> #include <linux/types.h> +#include <linux/refcount.h> +#include <linux/completion.h> + +#define SHRINKER_UNIT_BITS BITS_PER_LONG + +/* + * Bitmap and deferred work of shrinker::id corresponding to memcg-aware + * shrinkers, which have elements charged to the memcg. + */ +struct shrinker_info_unit { + atomic_long_t nr_deferred[SHRINKER_UNIT_BITS]; + DECLARE_BITMAP(map, SHRINKER_UNIT_BITS); +}; + +struct shrinker_info { + struct rcu_head rcu; + int map_nr_max; + struct shrinker_info_unit *unit[]; +}; /* * This struct is used to pass information from page reclaim to the shrinkers. @@ -70,6 +89,19 @@ struct shrinker { int seeks; /* seeks to recreate an obj */ unsigned flags; + /* + * The reference count of this shrinker. Registered shrinker have an + * initial refcount of 1, then the lookup operations are now allowed + * to use it via shrinker_try_get(). Later in the unregistration step, + * the initial refcount will be discarded, and will free the shrinker + * asynchronously via RCU after its refcount reaches 0. + */ + refcount_t refcount; + struct completion done; /* use to wait for refcount to reach 0 */ + struct rcu_head rcu; + + void *private_data; + /* These are for internal use */ struct list_head list; #ifdef CONFIG_MEMCG @@ -86,48 +118,39 @@ struct shrinker { }; #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */ -/* Flags */ -#define SHRINKER_REGISTERED (1 << 0) -#define SHRINKER_NUMA_AWARE (1 << 1) -#define SHRINKER_MEMCG_AWARE (1 << 2) +/* Internal flags */ +#define SHRINKER_REGISTERED BIT(0) +#define SHRINKER_ALLOCATED BIT(1) + +/* Flags for users to use */ +#define SHRINKER_NUMA_AWARE BIT(2) +#define SHRINKER_MEMCG_AWARE BIT(3) /* * It just makes sense when the shrinker is also MEMCG_AWARE for now, * non-MEMCG_AWARE shrinker should not have this flag set. */ -#define SHRINKER_NONSLAB (1 << 3) +#define SHRINKER_NONSLAB BIT(4) -extern int __printf(2, 3) prealloc_shrinker(struct shrinker *shrinker, - const char *fmt, ...); -extern void register_shrinker_prepared(struct shrinker *shrinker); -extern int __printf(2, 3) register_shrinker(struct shrinker *shrinker, - const char *fmt, ...); -extern void unregister_shrinker(struct shrinker *shrinker); -extern void free_prealloced_shrinker(struct shrinker *shrinker); -extern void synchronize_shrinkers(void); +__printf(2, 3) +struct shrinker *shrinker_alloc(unsigned int flags, const char *fmt, ...); +void shrinker_register(struct shrinker *shrinker); +void shrinker_free(struct shrinker *shrinker); -#ifdef CONFIG_SHRINKER_DEBUG -extern int shrinker_debugfs_add(struct shrinker *shrinker); -extern struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, - int *debugfs_id); -extern void shrinker_debugfs_remove(struct dentry *debugfs_entry, - int debugfs_id); -extern int __printf(2, 3) shrinker_debugfs_rename(struct shrinker *shrinker, - const char *fmt, ...); -#else /* CONFIG_SHRINKER_DEBUG */ -static inline int shrinker_debugfs_add(struct shrinker *shrinker) -{ - return 0; -} -static inline struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, - int *debugfs_id) +static inline bool shrinker_try_get(struct shrinker *shrinker) { - *debugfs_id = -1; - return NULL; + return refcount_inc_not_zero(&shrinker->refcount); } -static inline void shrinker_debugfs_remove(struct dentry *debugfs_entry, - int debugfs_id) + +static inline void shrinker_put(struct shrinker *shrinker) { + if (refcount_dec_and_test(&shrinker->refcount)) + complete(&shrinker->done); } + +#ifdef CONFIG_SHRINKER_DEBUG +extern int __printf(2, 3) shrinker_debugfs_rename(struct shrinker *shrinker, + const char *fmt, ...); +#else /* CONFIG_SHRINKER_DEBUG */ static inline __printf(2, 3) int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...) { |