diff options
Diffstat (limited to 'mm/shrinker.c')
| -rw-r--r-- | mm/shrinker.c | 809 |
1 files changed, 809 insertions, 0 deletions
diff --git a/mm/shrinker.c b/mm/shrinker.c new file mode 100644 index 0000000000..dc5d2a6fcf --- /dev/null +++ b/mm/shrinker.c @@ -0,0 +1,809 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/memcontrol.h> +#include <linux/rwsem.h> +#include <linux/shrinker.h> +#include <linux/rculist.h> +#include <trace/events/vmscan.h> + +#include "internal.h" + +LIST_HEAD(shrinker_list); +DEFINE_MUTEX(shrinker_mutex); + +#ifdef CONFIG_MEMCG +static int shrinker_nr_max; + +static inline int shrinker_unit_size(int nr_items) +{ + return (DIV_ROUND_UP(nr_items, SHRINKER_UNIT_BITS) * sizeof(struct shrinker_info_unit *)); +} + +static inline void shrinker_unit_free(struct shrinker_info *info, int start) +{ + struct shrinker_info_unit **unit; + int nr, i; + + if (!info) + return; + + unit = info->unit; + nr = DIV_ROUND_UP(info->map_nr_max, SHRINKER_UNIT_BITS); + + for (i = start; i < nr; i++) { + if (!unit[i]) + break; + + kfree(unit[i]); + unit[i] = NULL; + } +} + +static inline int shrinker_unit_alloc(struct shrinker_info *new, + struct shrinker_info *old, int nid) +{ + struct shrinker_info_unit *unit; + int nr = DIV_ROUND_UP(new->map_nr_max, SHRINKER_UNIT_BITS); + int start = old ? DIV_ROUND_UP(old->map_nr_max, SHRINKER_UNIT_BITS) : 0; + int i; + + for (i = start; i < nr; i++) { + unit = kzalloc_node(sizeof(*unit), GFP_KERNEL, nid); + if (!unit) { + shrinker_unit_free(new, start); + return -ENOMEM; + } + + new->unit[i] = unit; + } + + return 0; +} + +void free_shrinker_info(struct mem_cgroup *memcg) +{ + struct mem_cgroup_per_node *pn; + struct shrinker_info *info; + int nid; + + for_each_node(nid) { + pn = memcg->nodeinfo[nid]; + info = rcu_dereference_protected(pn->shrinker_info, true); + shrinker_unit_free(info, 0); + kvfree(info); + rcu_assign_pointer(pn->shrinker_info, NULL); + } +} + +int alloc_shrinker_info(struct mem_cgroup *memcg) +{ + struct shrinker_info *info; + int nid, ret = 0; + int array_size = 0; + + mutex_lock(&shrinker_mutex); + array_size = shrinker_unit_size(shrinker_nr_max); + for_each_node(nid) { + info = kvzalloc_node(sizeof(*info) + array_size, GFP_KERNEL, nid); + if (!info) + goto err; + info->map_nr_max = shrinker_nr_max; + if (shrinker_unit_alloc(info, NULL, nid)) + goto err; + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info); + } + mutex_unlock(&shrinker_mutex); + + return ret; + +err: + mutex_unlock(&shrinker_mutex); + free_shrinker_info(memcg); + return -ENOMEM; +} + +static struct shrinker_info *shrinker_info_protected(struct mem_cgroup *memcg, + int nid) +{ + return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, + lockdep_is_held(&shrinker_mutex)); +} + +static int expand_one_shrinker_info(struct mem_cgroup *memcg, int new_size, + int old_size, int new_nr_max) +{ + struct shrinker_info *new, *old; + struct mem_cgroup_per_node *pn; + int nid; + + for_each_node(nid) { + pn = memcg->nodeinfo[nid]; + old = shrinker_info_protected(memcg, nid); + /* Not yet online memcg */ + if (!old) + return 0; + + /* Already expanded this shrinker_info */ + if (new_nr_max <= old->map_nr_max) + continue; + + new = kvzalloc_node(sizeof(*new) + new_size, GFP_KERNEL, nid); + if (!new) + return -ENOMEM; + + new->map_nr_max = new_nr_max; + + memcpy(new->unit, old->unit, old_size); + if (shrinker_unit_alloc(new, old, nid)) { + kvfree(new); + return -ENOMEM; + } + + rcu_assign_pointer(pn->shrinker_info, new); + kvfree_rcu(old, rcu); + } + + return 0; +} + +static int expand_shrinker_info(int new_id) +{ + int ret = 0; + int new_nr_max = round_up(new_id + 1, SHRINKER_UNIT_BITS); + int new_size, old_size = 0; + struct mem_cgroup *memcg; + + if (!root_mem_cgroup) + goto out; + + lockdep_assert_held(&shrinker_mutex); + + new_size = shrinker_unit_size(new_nr_max); + old_size = shrinker_unit_size(shrinker_nr_max); + + memcg = mem_cgroup_iter(NULL, NULL, NULL); + do { + ret = expand_one_shrinker_info(memcg, new_size, old_size, + new_nr_max); + if (ret) { + mem_cgroup_iter_break(NULL, memcg); + goto out; + } + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); +out: + if (!ret) + shrinker_nr_max = new_nr_max; + + return ret; +} + +static inline int shrinker_id_to_index(int shrinker_id) +{ + return shrinker_id / SHRINKER_UNIT_BITS; +} + +static inline int shrinker_id_to_offset(int shrinker_id) +{ + return shrinker_id % SHRINKER_UNIT_BITS; +} + +static inline int calc_shrinker_id(int index, int offset) +{ + return index * SHRINKER_UNIT_BITS + offset; +} + +void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) +{ + if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { + struct shrinker_info *info; + struct shrinker_info_unit *unit; + + rcu_read_lock(); + info = rcu_dereference(memcg->nodeinfo[nid]->shrinker_info); + unit = info->unit[shrinker_id_to_index(shrinker_id)]; + if (!WARN_ON_ONCE(shrinker_id >= info->map_nr_max)) { + /* Pairs with smp mb in shrink_slab() */ + smp_mb__before_atomic(); + set_bit(shrinker_id_to_offset(shrinker_id), unit->map); + } + rcu_read_unlock(); + } +} + +static DEFINE_IDR(shrinker_idr); + +static int shrinker_memcg_alloc(struct shrinker *shrinker) +{ + int id, ret = -ENOMEM; + + if (mem_cgroup_disabled()) + return -ENOSYS; + + mutex_lock(&shrinker_mutex); + id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL); + if (id < 0) + goto unlock; + + if (id >= shrinker_nr_max) { + if (expand_shrinker_info(id)) { + idr_remove(&shrinker_idr, id); + goto unlock; + } + } + shrinker->id = id; + ret = 0; +unlock: + mutex_unlock(&shrinker_mutex); + return ret; +} + +static void shrinker_memcg_remove(struct shrinker *shrinker) +{ + int id = shrinker->id; + + BUG_ON(id < 0); + + lockdep_assert_held(&shrinker_mutex); + + idr_remove(&shrinker_idr, id); +} + +static long xchg_nr_deferred_memcg(int nid, struct shrinker *shrinker, + struct mem_cgroup *memcg) +{ + struct shrinker_info *info; + struct shrinker_info_unit *unit; + long nr_deferred; + + rcu_read_lock(); + info = rcu_dereference(memcg->nodeinfo[nid]->shrinker_info); + unit = info->unit[shrinker_id_to_index(shrinker->id)]; + nr_deferred = atomic_long_xchg(&unit->nr_deferred[shrinker_id_to_offset(shrinker->id)], 0); + rcu_read_unlock(); + + return nr_deferred; +} + +static long add_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, + struct mem_cgroup *memcg) +{ + struct shrinker_info *info; + struct shrinker_info_unit *unit; + long nr_deferred; + + rcu_read_lock(); + info = rcu_dereference(memcg->nodeinfo[nid]->shrinker_info); + unit = info->unit[shrinker_id_to_index(shrinker->id)]; + nr_deferred = + atomic_long_add_return(nr, &unit->nr_deferred[shrinker_id_to_offset(shrinker->id)]); + rcu_read_unlock(); + + return nr_deferred; +} + +void reparent_shrinker_deferred(struct mem_cgroup *memcg) +{ + int nid, index, offset; + long nr; + struct mem_cgroup *parent; + struct shrinker_info *child_info, *parent_info; + struct shrinker_info_unit *child_unit, *parent_unit; + + parent = parent_mem_cgroup(memcg); + if (!parent) + parent = root_mem_cgroup; + + /* Prevent from concurrent shrinker_info expand */ + mutex_lock(&shrinker_mutex); + for_each_node(nid) { + child_info = shrinker_info_protected(memcg, nid); + parent_info = shrinker_info_protected(parent, nid); + for (index = 0; index < shrinker_id_to_index(child_info->map_nr_max); index++) { + child_unit = child_info->unit[index]; + parent_unit = parent_info->unit[index]; + for (offset = 0; offset < SHRINKER_UNIT_BITS; offset++) { + nr = atomic_long_read(&child_unit->nr_deferred[offset]); + atomic_long_add(nr, &parent_unit->nr_deferred[offset]); + } + } + } + mutex_unlock(&shrinker_mutex); +} +#else +static int shrinker_memcg_alloc(struct shrinker *shrinker) +{ + return -ENOSYS; +} + +static void shrinker_memcg_remove(struct shrinker *shrinker) +{ +} + +static long xchg_nr_deferred_memcg(int nid, struct shrinker *shrinker, + struct mem_cgroup *memcg) +{ + return 0; +} + +static long add_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, + struct mem_cgroup *memcg) +{ + return 0; +} +#endif /* CONFIG_MEMCG */ + +static long xchg_nr_deferred(struct shrinker *shrinker, + struct shrink_control *sc) +{ + int nid = sc->nid; + + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) + nid = 0; + + if (sc->memcg && + (shrinker->flags & SHRINKER_MEMCG_AWARE)) + return xchg_nr_deferred_memcg(nid, shrinker, + sc->memcg); + + return atomic_long_xchg(&shrinker->nr_deferred[nid], 0); +} + + +static long add_nr_deferred(long nr, struct shrinker *shrinker, + struct shrink_control *sc) +{ + int nid = sc->nid; + + if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) + nid = 0; + + if (sc->memcg && + (shrinker->flags & SHRINKER_MEMCG_AWARE)) + return add_nr_deferred_memcg(nr, nid, shrinker, + sc->memcg); + + return atomic_long_add_return(nr, &shrinker->nr_deferred[nid]); +} + +#define SHRINK_BATCH 128 + +static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, + struct shrinker *shrinker, int priority) +{ + unsigned long freed = 0; + unsigned long long delta; + long total_scan; + long freeable; + long nr; + long new_nr; + long batch_size = shrinker->batch ? shrinker->batch + : SHRINK_BATCH; + long scanned = 0, next_deferred; + + freeable = shrinker->count_objects(shrinker, shrinkctl); + if (freeable == 0 || freeable == SHRINK_EMPTY) + return freeable; + + /* + * copy the current shrinker scan count into a local variable + * and zero it so that other concurrent shrinker invocations + * don't also do this scanning work. + */ + nr = xchg_nr_deferred(shrinker, shrinkctl); + + if (shrinker->seeks) { + delta = freeable >> priority; + delta *= 4; + do_div(delta, shrinker->seeks); + } else { + /* + * These objects don't require any IO to create. Trim + * them aggressively under memory pressure to keep + * them from causing refetches in the IO caches. + */ + delta = freeable / 2; + } + + total_scan = nr >> priority; + total_scan += delta; + total_scan = min(total_scan, (2 * freeable)); + + trace_mm_shrink_slab_start(shrinker, shrinkctl, nr, + freeable, delta, total_scan, priority); + + /* + * Normally, we should not scan less than batch_size objects in one + * pass to avoid too frequent shrinker calls, but if the slab has less + * than batch_size objects in total and we are really tight on memory, + * we will try to reclaim all available objects, otherwise we can end + * up failing allocations although there are plenty of reclaimable + * objects spread over several slabs with usage less than the + * batch_size. + * + * We detect the "tight on memory" situations by looking at the total + * number of objects we want to scan (total_scan). If it is greater + * than the total number of objects on slab (freeable), we must be + * scanning at high prio and therefore should try to reclaim as much as + * possible. + */ + while (total_scan >= batch_size || + total_scan >= freeable) { + unsigned long ret; + unsigned long nr_to_scan = min(batch_size, total_scan); + + shrinkctl->nr_to_scan = nr_to_scan; + shrinkctl->nr_scanned = nr_to_scan; + ret = shrinker->scan_objects(shrinker, shrinkctl); + if (ret == SHRINK_STOP) + break; + freed += ret; + + count_vm_events(SLABS_SCANNED, shrinkctl->nr_scanned); + total_scan -= shrinkctl->nr_scanned; + scanned += shrinkctl->nr_scanned; + + cond_resched(); + } + + /* + * The deferred work is increased by any new work (delta) that wasn't + * done, decreased by old deferred work that was done now. + * + * And it is capped to two times of the freeable items. + */ + next_deferred = max_t(long, (nr + delta - scanned), 0); + next_deferred = min(next_deferred, (2 * freeable)); + + /* + * move the unused scan count back into the shrinker in a + * manner that handles concurrent updates. + */ + new_nr = add_nr_deferred(next_deferred, shrinker, shrinkctl); + + trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan); + return freed; +} + +#ifdef CONFIG_MEMCG +static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, + struct mem_cgroup *memcg, int priority) +{ + struct shrinker_info *info; + unsigned long ret, freed = 0; + int offset, index = 0; + + if (!mem_cgroup_online(memcg)) + return 0; + + /* + * lockless algorithm of memcg shrink. + * + * The shrinker_info may be freed asynchronously via RCU in the + * expand_one_shrinker_info(), so the rcu_read_lock() needs to be used + * to ensure the existence of the shrinker_info. + * + * The shrinker_info_unit is never freed unless its corresponding memcg + * is destroyed. Here we already hold the refcount of memcg, so the + * memcg will not be destroyed, and of course shrinker_info_unit will + * not be freed. + * + * So in the memcg shrink: + * step 1: use rcu_read_lock() to guarantee existence of the + * shrinker_info. + * step 2: after getting shrinker_info_unit we can safely release the + * RCU lock. + * step 3: traverse the bitmap and calculate shrinker_id + * step 4: use rcu_read_lock() to guarantee existence of the shrinker. + * step 5: use shrinker_id to find the shrinker, then use + * shrinker_try_get() to guarantee existence of the shrinker, + * then we can release the RCU lock to do do_shrink_slab() that + * may sleep. + * step 6: do shrinker_put() paired with step 5 to put the refcount, + * if the refcount reaches 0, then wake up the waiter in + * shrinker_free() by calling complete(). + * Note: here is different from the global shrink, we don't + * need to acquire the RCU lock to guarantee existence of + * the shrinker, because we don't need to use this + * shrinker to traverse the next shrinker in the bitmap. + * step 7: we have already exited the read-side of rcu critical section + * before calling do_shrink_slab(), the shrinker_info may be + * released in expand_one_shrinker_info(), so go back to step 1 + * to reacquire the shrinker_info. + */ +again: + rcu_read_lock(); + info = rcu_dereference(memcg->nodeinfo[nid]->shrinker_info); + if (unlikely(!info)) + goto unlock; + + if (index < shrinker_id_to_index(info->map_nr_max)) { + struct shrinker_info_unit *unit; + + unit = info->unit[index]; + + rcu_read_unlock(); + + for_each_set_bit(offset, unit->map, SHRINKER_UNIT_BITS) { + struct shrink_control sc = { + .gfp_mask = gfp_mask, + .nid = nid, + .memcg = memcg, + }; + struct shrinker *shrinker; + int shrinker_id = calc_shrinker_id(index, offset); + + rcu_read_lock(); + shrinker = idr_find(&shrinker_idr, shrinker_id); + if (unlikely(!shrinker || !shrinker_try_get(shrinker))) { + clear_bit(offset, unit->map); + rcu_read_unlock(); + continue; + } + rcu_read_unlock(); + + /* Call non-slab shrinkers even though kmem is disabled */ + if (!memcg_kmem_online() && + !(shrinker->flags & SHRINKER_NONSLAB)) + continue; + + ret = do_shrink_slab(&sc, shrinker, priority); + if (ret == SHRINK_EMPTY) { + clear_bit(offset, unit->map); + /* + * After the shrinker reported that it had no objects to + * free, but before we cleared the corresponding bit in + * the memcg shrinker map, a new object might have been + * added. To make sure, we have the bit set in this + * case, we invoke the shrinker one more time and reset + * the bit if it reports that it is not empty anymore. + * The memory barrier here pairs with the barrier in + * set_shrinker_bit(): + * + * list_lru_add() shrink_slab_memcg() + * list_add_tail() clear_bit() + * <MB> <MB> + * set_bit() do_shrink_slab() + */ + smp_mb__after_atomic(); + ret = do_shrink_slab(&sc, shrinker, priority); + if (ret == SHRINK_EMPTY) + ret = 0; + else + set_shrinker_bit(memcg, nid, shrinker_id); + } + freed += ret; + shrinker_put(shrinker); + } + + index++; + goto again; + } +unlock: + rcu_read_unlock(); + return freed; +} +#else /* !CONFIG_MEMCG */ +static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, + struct mem_cgroup *memcg, int priority) +{ + return 0; +} +#endif /* CONFIG_MEMCG */ + +/** + * shrink_slab - shrink slab caches + * @gfp_mask: allocation context + * @nid: node whose slab caches to target + * @memcg: memory cgroup whose slab caches to target + * @priority: the reclaim priority + * + * Call the shrink functions to age shrinkable caches. + * + * @nid is passed along to shrinkers with SHRINKER_NUMA_AWARE set, + * unaware shrinkers will receive a node id of 0 instead. + * + * @memcg specifies the memory cgroup to target. Unaware shrinkers + * are called only if it is the root cgroup. + * + * @priority is sc->priority, we take the number of objects and >> by priority + * in order to get the scan target. + * + * Returns the number of reclaimed slab objects. + */ +unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, + int priority) +{ + unsigned long ret, freed = 0; + struct shrinker *shrinker; + + /* + * The root memcg might be allocated even though memcg is disabled + * via "cgroup_disable=memory" boot parameter. This could make + * mem_cgroup_is_root() return false, then just run memcg slab + * shrink, but skip global shrink. This may result in premature + * oom. + */ + if (!mem_cgroup_disabled() && !mem_cgroup_is_root(memcg)) + return shrink_slab_memcg(gfp_mask, nid, memcg, priority); + + /* + * lockless algorithm of global shrink. + * + * In the unregistration setp, the shrinker will be freed asynchronously + * via RCU after its refcount reaches 0. So both rcu_read_lock() and + * shrinker_try_get() can be used to ensure the existence of the shrinker. + * + * So in the global shrink: + * step 1: use rcu_read_lock() to guarantee existence of the shrinker + * and the validity of the shrinker_list walk. + * step 2: use shrinker_try_get() to try get the refcount, if successful, + * then the existence of the shrinker can also be guaranteed, + * so we can release the RCU lock to do do_shrink_slab() that + * may sleep. + * step 3: *MUST* to reacquire the RCU lock before calling shrinker_put(), + * which ensures that neither this shrinker nor the next shrinker + * will be freed in the next traversal operation. + * step 4: do shrinker_put() paired with step 2 to put the refcount, + * if the refcount reaches 0, then wake up the waiter in + * shrinker_free() by calling complete(). + */ + rcu_read_lock(); + list_for_each_entry_rcu(shrinker, &shrinker_list, list) { + struct shrink_control sc = { + .gfp_mask = gfp_mask, + .nid = nid, + .memcg = memcg, + }; + + if (!shrinker_try_get(shrinker)) + continue; + + rcu_read_unlock(); + + ret = do_shrink_slab(&sc, shrinker, priority); + if (ret == SHRINK_EMPTY) + ret = 0; + freed += ret; + + rcu_read_lock(); + shrinker_put(shrinker); + } + + rcu_read_unlock(); + cond_resched(); + 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 = shrinker_memcg_alloc(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; + } + + mutex_lock(&shrinker_mutex); + list_add_tail_rcu(&shrinker->list, &shrinker_list); + shrinker->flags |= SHRINKER_REGISTERED; + shrinker_debugfs_add(shrinker); + mutex_unlock(&shrinker_mutex); + + init_completion(&shrinker->done); + /* + * Now the shrinker is fully set up, take the first reference to it to + * indicate that lookup operations are now allowed to use it via + * shrinker_try_get(). + */ + refcount_set(&shrinker->refcount, 1); +} +EXPORT_SYMBOL_GPL(shrinker_register); + +static void shrinker_free_rcu_cb(struct rcu_head *head) +{ + struct shrinker *shrinker = container_of(head, struct shrinker, rcu); + + kfree(shrinker->nr_deferred); + kfree(shrinker); +} + +void shrinker_free(struct shrinker *shrinker) +{ + struct dentry *debugfs_entry = NULL; + int debugfs_id; + + if (!shrinker) + return; + + if (shrinker->flags & SHRINKER_REGISTERED) { + /* drop the initial refcount */ + shrinker_put(shrinker); + /* + * Wait for all lookups of the shrinker to complete, after that, + * no shrinker is running or will run again, then we can safely + * free it asynchronously via RCU and safely free the structure + * where the shrinker is located, such as super_block etc. + */ + wait_for_completion(&shrinker->done); + } + + mutex_lock(&shrinker_mutex); + if (shrinker->flags & SHRINKER_REGISTERED) { + /* + * Now we can safely remove it from the shrinker_list and then + * free it. + */ + list_del_rcu(&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) + shrinker_memcg_remove(shrinker); + mutex_unlock(&shrinker_mutex); + + if (debugfs_entry) + shrinker_debugfs_remove(debugfs_entry, debugfs_id); + + call_rcu(&shrinker->rcu, shrinker_free_rcu_cb); +} +EXPORT_SYMBOL_GPL(shrinker_free); |