bcachefs: Kill allocator threads & freelists

Now that we have new persistent data structures for the allocator, this
patch converts the allocator to use them.

Now, foreground bucket allocation uses the freespace btree to find
buckets to allocate, instead of popping buckets off the freelist.

The background allocator threads are no longer needed and are deleted,
as well as the allocator freelists. Now we only need background tasks
for invalidating buckets containing cached data (when we are low on
empty buckets), and for issuing discards.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 7 insertions, 40 deletions

diff --git a/fs/bcachefs/sysfs.c b/fs/bcachefs/sysfs.c
index ec672134cb18..e995b84b6172 100644
--- a/fs/bcachefs/sysfs.c
+++ b/fs/bcachefs/sysfs.c
@@ -170,7 +170,6 @@ read_attribute(congested);
 
 read_attribute(btree_avg_write_size);
 
-read_attribute(reserve_stats);
 read_attribute(btree_cache_size);
 read_attribute(compression_stats);
 read_attribute(journal_debug);
@@ -186,11 +185,11 @@ read_attribute(internal_uuid);
 
 read_attribute(has_data);
 read_attribute(alloc_debug);
-write_attribute(wake_allocator);
 
 read_attribute(read_realloc_races);
 read_attribute(extent_migrate_done);
 read_attribute(extent_migrate_raced);
+read_attribute(bucket_alloc_fail);
 
 rw_attribute(discard);
 rw_attribute(label);
@@ -377,6 +376,8 @@ SHOW(bch2_fs)
 		    atomic_long_read(&c->extent_migrate_done));
 	sysfs_print(extent_migrate_raced,
 		    atomic_long_read(&c->extent_migrate_raced));
+	sysfs_print(bucket_alloc_fail,
+		    atomic_long_read(&c->bucket_alloc_fail));
 
 	sysfs_printf(btree_gc_periodic, "%u",	(int) c->btree_gc_periodic);
 
@@ -577,6 +578,7 @@ struct attribute *bch2_fs_internal_files[] = {
 	&sysfs_read_realloc_races,
 	&sysfs_extent_migrate_done,
 	&sysfs_extent_migrate_raced,
+	&sysfs_bucket_alloc_fail,
 
 	&sysfs_gc_gens_pos,
 
@@ -705,24 +707,6 @@ struct attribute *bch2_fs_time_stats_files[] = {
 	NULL
 };
 
-static void reserve_stats_to_text(struct printbuf *out, struct bch_dev *ca)
-{
-	enum alloc_reserve i;
-
-	spin_lock(&ca->fs->freelist_lock);
-
-	pr_buf(out, "free_inc:\t%zu\t%zu\n",
-	       fifo_used(&ca->free_inc),
-	       ca->free_inc.size);
-
-	for (i = 0; i < RESERVE_NR; i++)
-		pr_buf(out, "free[%u]:\t%zu\t%zu\n", i,
-		       fifo_used(&ca->free[i]),
-		       ca->free[i].size);
-
-	spin_unlock(&ca->fs->freelist_lock);
-}
-
 static void dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
 {
 	struct bch_fs *c = ca->fs;
@@ -748,9 +732,6 @@ static void dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
 	       "ec\t%16llu\n"
 	       "available%15llu\n"
 	       "\n"
-	       "free_inc\t\t%zu/%zu\n"
-	       "free[RESERVE_MOVINGGC]\t%zu/%zu\n"
-	       "free[RESERVE_NONE]\t%zu/%zu\n"
 	       "freelist_wait\t\t%s\n"
 	       "open buckets allocated\t%u\n"
 	       "open buckets this dev\t%u\n"
@@ -758,13 +739,9 @@ static void dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
 	       "open_buckets_wait\t%s\n"
 	       "open_buckets_btree\t%u\n"
 	       "open_buckets_user\t%u\n"
-	       "btree reserve cache\t%u\n"
-	       "thread state:\t\t%s\n",
+	       "btree reserve cache\t%u\n",
 	       stats.buckets_ec,
-	       __dev_buckets_available(ca, stats),
-	       fifo_used(&ca->free_inc),		ca->free_inc.size,
-	       fifo_used(&ca->free[RESERVE_movinggc]),	ca->free[RESERVE_movinggc].size,
-	       fifo_used(&ca->free[RESERVE_none]),	ca->free[RESERVE_none].size,
+	       __dev_buckets_available(ca, stats, RESERVE_none),
 	       c->freelist_wait.list.first		? "waiting" : "empty",
 	       OPEN_BUCKETS_COUNT - c->open_buckets_nr_free,
 	       ca->nr_open_buckets,
@@ -772,8 +749,7 @@ static void dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
 	       c->open_buckets_wait.list.first		? "waiting" : "empty",
 	       nr[BCH_DATA_btree],
 	       nr[BCH_DATA_user],
-	       c->btree_reserve_cache_nr,
-	       bch2_allocator_states[ca->allocator_state]);
+	       c->btree_reserve_cache_nr);
 }
 
 static const char * const bch2_rw[] = {
@@ -848,9 +824,6 @@ SHOW(bch2_dev)
 		     clamp(atomic_read(&ca->congested), 0, CONGESTED_MAX)
 		     * 100 / CONGESTED_MAX);
 
-	if (attr == &sysfs_reserve_stats)
-		reserve_stats_to_text(out, ca);
-
 	if (attr == &sysfs_alloc_debug)
 		dev_alloc_debug_to_text(out, ca);
 
@@ -890,9 +863,6 @@ STORE(bch2_dev)
 			return ret;
 	}
 
-	if (attr == &sysfs_wake_allocator)
-		bch2_wake_allocator(ca);
-
 	return size;
 }
 SYSFS_OPS(bch2_dev);
@@ -918,11 +888,8 @@ struct attribute *bch2_dev_files[] = {
 	&sysfs_io_latency_stats_write,
 	&sysfs_congested,
 
-	&sysfs_reserve_stats,
-
 	/* debug: */
 	&sysfs_alloc_debug,
-	&sysfs_wake_allocator,
 	NULL
 };