bcache: Use a mempool for mergesort temporary space

It was a single element mempool before, it's slightly cleaner to just use a real
mempool.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index eb6f2e6..25f0172 100644 (file)
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -645,12 +645,7 @@ struct cache_set {
         */
        mempool_t               *fill_iter;
 
-       /*
-        * btree_sort() is a merge sort and requires temporary space - single
-        * element mempool
-        */
-       struct mutex            sort_lock;
-       struct bset             *sort;
+       mempool_t               *sort_pool;
        unsigned                sort_crit_factor;
 
        /* List of buckets we're currently writing data to */

diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index 98f0ced..e688265 100644 (file)
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -1047,11 +1047,12 @@ static void __btree_sort(struct btree *b, struct btree_iter *iter,
 {
        uint64_t start_time;
        bool remove_stale = !b->written;
+       bool used_mempool = false;
        struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOIO,
                                                     order);
        if (!out) {
-               mutex_lock(&b->c->sort_lock);
-               out = b->c->sort;
+               out = page_address(mempool_alloc(b->c->sort_pool, GFP_NOIO));
+               used_mempool = true;
                order = ilog2(bucket_pages(b->c));
        }
 
@@ -1071,17 +1072,14 @@ static void __btree_sort(struct btree *b, struct btree_iter *iter,
                out->seq        = b->sets[0].data->seq;
                out->version    = b->sets[0].data->version;
                swap(out, b->sets[0].data);
-
-               if (b->c->sort == b->sets[0].data)
-                       b->c->sort = out;
        } else {
                b->sets[start].data->keys = out->keys;
                memcpy(b->sets[start].data->start, out->start,
                       (void *) end(out) - (void *) out->start);
        }
 
-       if (out == b->c->sort)
-               mutex_unlock(&b->c->sort_lock);
+       if (used_mempool)
+               mempool_free(virt_to_page(out), b->c->sort_pool);
        else
                free_pages((unsigned long) out, order);
 

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 677a604..d05e756 100644 (file)
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1352,7 +1352,6 @@ static void cache_set_free(struct closure *cl)
                        kobject_put(&ca->kobj);
 
        free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));
-       free_pages((unsigned long) c->sort, ilog2(bucket_pages(c)));
 
        if (c->bio_split)
                bioset_free(c->bio_split);
@@ -1489,7 +1488,6 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
        init_waitqueue_head(&c->try_wait);
        init_waitqueue_head(&c->bucket_wait);
        sema_init(&c->uuid_write_mutex, 1);
-       mutex_init(&c->sort_lock);
 
        spin_lock_init(&c->sort_time.lock);
        spin_lock_init(&c->btree_gc_time.lock);
@@ -1519,7 +1517,8 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
                                bucket_pages(c))) ||
            !(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) ||
            !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
-           !(c->sort = alloc_bucket_pages(GFP_KERNEL, c)) ||
+           !(c->sort_pool = mempool_create_page_pool(1,
+                               ilog2(bucket_pages(c)))) ||
            !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
            bch_journal_alloc(c) ||
            bch_btree_cache_alloc(c) ||