diff options
| -rw-r--r-- | include/linux/shrinker.h | 19 | ||||
| -rw-r--r-- | mm/internal.h | 22 | ||||
| -rw-r--r-- | mm/shrinker.c | 106 | ||||
| -rw-r--r-- | mm/shrinker_debug.c | 3 |
4 files changed, 142 insertions, 8 deletions
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 6b5843c3b827..f4a5249f00b2 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -70,6 +70,8 @@ struct shrinker { int seeks; /* seeks to recreate an obj */ unsigned flags; + void *private_data; + /* These are for internal use */ struct list_head list; #ifdef CONFIG_MEMCG @@ -86,15 +88,22 @@ 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) + +struct shrinker *shrinker_alloc(unsigned int flags, const char *fmt, ...); +void shrinker_register(struct shrinker *shrinker); +void shrinker_free(struct shrinker *shrinker); extern int __printf(2, 3) prealloc_shrinker(struct shrinker *shrinker, const char *fmt, ...); diff --git a/mm/internal.h b/mm/internal.h index 0471d6326d01..a273f4d948d8 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1160,6 +1160,20 @@ unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, int priority); #ifdef CONFIG_SHRINKER_DEBUG +static inline int shrinker_debugfs_name_alloc(struct shrinker *shrinker, + const char *fmt, va_list ap) +{ + shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, ap); + + return shrinker->name ? 0 : -ENOMEM; +} + +static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) +{ + kfree_const(shrinker->name); + shrinker->name = NULL; +} + extern int shrinker_debugfs_add(struct shrinker *shrinker); extern struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, int *debugfs_id); @@ -1170,6 +1184,14 @@ static inline int shrinker_debugfs_add(struct shrinker *shrinker) { return 0; } +static inline int shrinker_debugfs_name_alloc(struct shrinker *shrinker, + const char *fmt, va_list ap) +{ + return 0; +} +static inline void shrinker_debugfs_name_free(struct shrinker *shrinker) +{ +} static inline struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, int *debugfs_id) { diff --git a/mm/shrinker.c b/mm/shrinker.c index a16cd448b924..d1032a4d5684 100644 --- a/mm/shrinker.c +++ b/mm/shrinker.c @@ -550,6 +550,112 @@ out: return freed; } +struct shrinker *shrinker_alloc(unsigned int flags, const char *fmt, ...) +{ + struct shrinker *shrinker; + unsigned int size; + va_list ap; + int err; + + shrinker = kzalloc(sizeof(struct shrinker), GFP_KERNEL); + if (!shrinker) + return NULL; + + va_start(ap, fmt); + err = shrinker_debugfs_name_alloc(shrinker, fmt, ap); + va_end(ap); + if (err) + goto err_name; + + shrinker->flags = flags | SHRINKER_ALLOCATED; + shrinker->seeks = DEFAULT_SEEKS; + + if (flags & SHRINKER_MEMCG_AWARE) { + err = prealloc_memcg_shrinker(shrinker); + if (err == -ENOSYS) { + /* Memcg is not supported, fallback to non-memcg-aware shrinker. */ + shrinker->flags &= ~SHRINKER_MEMCG_AWARE; + goto non_memcg; + } + + if (err) + goto err_flags; + + return shrinker; + } + +non_memcg: + /* + * The nr_deferred is available on per memcg level for memcg aware + * shrinkers, so only allocate nr_deferred in the following cases: + * - non-memcg-aware shrinkers + * - !CONFIG_MEMCG + * - memcg is disabled by kernel command line + */ + size = sizeof(*shrinker->nr_deferred); + if (flags & SHRINKER_NUMA_AWARE) + size *= nr_node_ids; + + shrinker->nr_deferred = kzalloc(size, GFP_KERNEL); + if (!shrinker->nr_deferred) + goto err_flags; + + return shrinker; + +err_flags: + shrinker_debugfs_name_free(shrinker); +err_name: + kfree(shrinker); + return NULL; +} +EXPORT_SYMBOL_GPL(shrinker_alloc); + +void shrinker_register(struct shrinker *shrinker) +{ + if (unlikely(!(shrinker->flags & SHRINKER_ALLOCATED))) { + pr_warn("Must use shrinker_alloc() to dynamically allocate the shrinker"); + return; + } + + down_write(&shrinker_rwsem); + list_add_tail(&shrinker->list, &shrinker_list); + shrinker->flags |= SHRINKER_REGISTERED; + shrinker_debugfs_add(shrinker); + up_write(&shrinker_rwsem); +} +EXPORT_SYMBOL_GPL(shrinker_register); + +void shrinker_free(struct shrinker *shrinker) +{ + struct dentry *debugfs_entry = NULL; + int debugfs_id; + + if (!shrinker) + return; + + down_write(&shrinker_rwsem); + if (shrinker->flags & SHRINKER_REGISTERED) { + list_del(&shrinker->list); + debugfs_entry = shrinker_debugfs_detach(shrinker, &debugfs_id); + shrinker->flags &= ~SHRINKER_REGISTERED; + } + + shrinker_debugfs_name_free(shrinker); + + if (shrinker->flags & SHRINKER_MEMCG_AWARE) + unregister_memcg_shrinker(shrinker); + up_write(&shrinker_rwsem); + + if (debugfs_entry) + shrinker_debugfs_remove(debugfs_entry, debugfs_id); + + kfree(shrinker->nr_deferred); + shrinker->nr_deferred = NULL; + + kfree(shrinker); +} +EXPORT_SYMBOL_GPL(shrinker_free); + /* * Add a shrinker callback to be called from the vm. */ diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index e4ce509f619e..24aebe7c24cc 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -241,9 +241,6 @@ struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, lockdep_assert_held(&shrinker_rwsem); - kfree_const(shrinker->name); - shrinker->name = NULL; - *debugfs_id = entry ? shrinker->debugfs_id : -1; shrinker->debugfs_entry = NULL; |