[PATCH v4 32/48] mbcache: dynamically allocate the mbcache shrinker
From: Qi Zheng <hidden>
Date: 2023-08-07 11:21:11
Also in:
dm-devel, dri-devel, kvm, linux-arm-msm, linux-bcache, linux-btrfs, linux-ext4, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-nfs, linux-raid, linux-xfs, lkml, rcu, xen-devel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the mbcache shrinker, so that it can be freed asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU read-side critical section when releasing the struct mb_cache. Signed-off-by: Qi Zheng <redacted> Reviewed-by: Muchun Song <redacted> --- fs/mbcache.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 2a4b8b549e93..0d1e24e9a5e3 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c@@ -37,7 +37,7 @@ struct mb_cache { struct list_head c_list; /* Number of entries in cache */ unsigned long c_entry_count; - struct shrinker c_shrink; + struct shrinker *c_shrink; /* Work for shrinking when the cache has too many entries */ struct work_struct c_shrink_work; };
@@ -293,8 +293,7 @@ EXPORT_SYMBOL(mb_cache_entry_touch); static unsigned long mb_cache_count(struct shrinker *shrink, struct shrink_control *sc) { - struct mb_cache *cache = container_of(shrink, struct mb_cache, - c_shrink); + struct mb_cache *cache = shrink->private_data; return cache->c_entry_count; }
@@ -333,8 +332,7 @@ static unsigned long mb_cache_shrink(struct mb_cache *cache, static unsigned long mb_cache_scan(struct shrinker *shrink, struct shrink_control *sc) { - struct mb_cache *cache = container_of(shrink, struct mb_cache, - c_shrink); + struct mb_cache *cache = shrink->private_data; return mb_cache_shrink(cache, sc->nr_to_scan); }
@@ -377,15 +375,20 @@ struct mb_cache *mb_cache_create(int bucket_bits) for (i = 0; i < bucket_count; i++) INIT_HLIST_BL_HEAD(&cache->c_hash[i]); - cache->c_shrink.count_objects = mb_cache_count; - cache->c_shrink.scan_objects = mb_cache_scan; - cache->c_shrink.seeks = DEFAULT_SEEKS; - if (register_shrinker(&cache->c_shrink, "mbcache-shrinker")) { + cache->c_shrink = shrinker_alloc(0, "mbcache-shrinker"); + if (!cache->c_shrink) { kfree(cache->c_hash); kfree(cache); goto err_out; } + cache->c_shrink->count_objects = mb_cache_count; + cache->c_shrink->scan_objects = mb_cache_scan; + cache->c_shrink->seeks = DEFAULT_SEEKS; + cache->c_shrink->private_data = cache; + + shrinker_register(cache->c_shrink); + INIT_WORK(&cache->c_shrink_work, mb_cache_shrink_worker); return cache;
@@ -406,7 +409,7 @@ void mb_cache_destroy(struct mb_cache *cache) { struct mb_cache_entry *entry, *next; - unregister_shrinker(&cache->c_shrink); + shrinker_free(cache->c_shrink); /* * We don't bother with any locking. Cache must not be used at this
--
2.30.2