[PATCH v3 30/49] bcache: dynamically allocate the md-bcache shrinker
From: Qi Zheng <hidden>
Date: 2023-07-27 08:22:45
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-xfs, lkml, netdev, rcu, xen-devel
Subsystem:
bcache (block layer cache), the rest · Maintainers:
Coly Li, Kent Overstreet, Linus Torvalds
In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the md-bcache 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 cache_set. Signed-off-by: Qi Zheng <redacted> --- drivers/md/bcache/bcache.h | 2 +- drivers/md/bcache/btree.c | 27 ++++++++++++++++----------- drivers/md/bcache/sysfs.c | 3 ++- 3 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 5a79bb3c272f..c622bc50f81b 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h@@ -541,7 +541,7 @@ struct cache_set { struct bio_set bio_split; /* For the btree cache */ - struct shrinker shrink; + struct shrinker *shrink; /* For the btree cache and anything allocation related */ struct mutex bucket_lock;
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index fd121a61f17c..ae5cbb55861f 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c@@ -667,7 +667,7 @@ static int mca_reap(struct btree *b, unsigned int min_order, bool flush) static unsigned long bch_mca_scan(struct shrinker *shrink, struct shrink_control *sc) { - struct cache_set *c = container_of(shrink, struct cache_set, shrink); + struct cache_set *c = shrink->private_data; struct btree *b, *t; unsigned long i, nr = sc->nr_to_scan; unsigned long freed = 0;
@@ -734,7 +734,7 @@ static unsigned long bch_mca_scan(struct shrinker *shrink, static unsigned long bch_mca_count(struct shrinker *shrink, struct shrink_control *sc) { - struct cache_set *c = container_of(shrink, struct cache_set, shrink); + struct cache_set *c = shrink->private_data; if (c->shrinker_disabled) return 0;
@@ -752,8 +752,8 @@ void bch_btree_cache_free(struct cache_set *c) closure_init_stack(&cl); - if (c->shrink.list.next) - unregister_shrinker(&c->shrink); + if (c->shrink) + shrinker_free(c->shrink); mutex_lock(&c->bucket_lock);
@@ -828,14 +828,19 @@ int bch_btree_cache_alloc(struct cache_set *c) c->verify_data = NULL; #endif - c->shrink.count_objects = bch_mca_count; - c->shrink.scan_objects = bch_mca_scan; - c->shrink.seeks = 4; - c->shrink.batch = c->btree_pages * 2; + c->shrink = shrinker_alloc(0, "md-bcache:%pU", c->set_uuid); + if (!c->shrink) { + pr_warn("bcache: %s: could not allocate shrinker\n", __func__); + return 0; + } + + c->shrink->count_objects = bch_mca_count; + c->shrink->scan_objects = bch_mca_scan; + c->shrink->seeks = 4; + c->shrink->batch = c->btree_pages * 2; + c->shrink->private_data = c; - if (register_shrinker(&c->shrink, "md-bcache:%pU", c->set_uuid)) - pr_warn("bcache: %s: could not register shrinker\n", - __func__); + shrinker_register(c->shrink); return 0; }
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 0e2c1880f60b..45d8af755de6 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c@@ -866,7 +866,8 @@ STORE(__bch_cache_set) sc.gfp_mask = GFP_KERNEL; sc.nr_to_scan = strtoul_or_return(buf); - c->shrink.scan_objects(&c->shrink, &sc); + if (c->shrink) + c->shrink->scan_objects(c->shrink, &sc); } sysfs_strtoul_clamp(congested_read_threshold_us,
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2.30.2