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Diffstat (limited to 'drivers/md/bcache/btree.c')
-rw-r--r--drivers/md/bcache/btree.c63
1 files changed, 54 insertions, 9 deletions
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 547c9eedc2f4..c19f7716df88 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -90,6 +90,9 @@
#define MAX_NEED_GC 64
#define MAX_SAVE_PRIO 72
+#define MAX_GC_TIMES 100
+#define MIN_GC_NODES 100
+#define GC_SLEEP_MS 100
#define PTR_DIRTY_BIT (((uint64_t) 1 << 36))
@@ -1008,6 +1011,13 @@ retry:
BUG_ON(b->level != level);
}
+ if (btree_node_io_error(b)) {
+ rw_unlock(write, b);
+ return ERR_PTR(-EIO);
+ }
+
+ BUG_ON(!b->written);
+
b->parent = parent;
b->accessed = 1;
@@ -1019,13 +1029,6 @@ retry:
for (; i <= b->keys.nsets; i++)
prefetch(b->keys.set[i].data);
- if (btree_node_io_error(b)) {
- rw_unlock(write, b);
- return ERR_PTR(-EIO);
- }
-
- BUG_ON(!b->written);
-
return b;
}
@@ -1520,6 +1523,32 @@ static unsigned btree_gc_count_keys(struct btree *b)
return ret;
}
+static size_t btree_gc_min_nodes(struct cache_set *c)
+{
+ size_t min_nodes;
+
+ /*
+ * Since incremental GC would stop 100ms when front
+ * side I/O comes, so when there are many btree nodes,
+ * if GC only processes constant (100) nodes each time,
+ * GC would last a long time, and the front side I/Os
+ * would run out of the buckets (since no new bucket
+ * can be allocated during GC), and be blocked again.
+ * So GC should not process constant nodes, but varied
+ * nodes according to the number of btree nodes, which
+ * realized by dividing GC into constant(100) times,
+ * so when there are many btree nodes, GC can process
+ * more nodes each time, otherwise, GC will process less
+ * nodes each time (but no less than MIN_GC_NODES)
+ */
+ min_nodes = c->gc_stats.nodes / MAX_GC_TIMES;
+ if (min_nodes < MIN_GC_NODES)
+ min_nodes = MIN_GC_NODES;
+
+ return min_nodes;
+}
+
+
static int btree_gc_recurse(struct btree *b, struct btree_op *op,
struct closure *writes, struct gc_stat *gc)
{
@@ -1585,6 +1614,13 @@ static int btree_gc_recurse(struct btree *b, struct btree_op *op,
memmove(r + 1, r, sizeof(r[0]) * (GC_MERGE_NODES - 1));
r->b = NULL;
+ if (atomic_read(&b->c->search_inflight) &&
+ gc->nodes >= gc->nodes_pre + btree_gc_min_nodes(b->c)) {
+ gc->nodes_pre = gc->nodes;
+ ret = -EAGAIN;
+ break;
+ }
+
if (need_resched()) {
ret = -EAGAIN;
break;
@@ -1753,7 +1789,10 @@ static void bch_btree_gc(struct cache_set *c)
closure_sync(&writes);
cond_resched();
- if (ret && ret != -EAGAIN)
+ if (ret == -EAGAIN)
+ schedule_timeout_interruptible(msecs_to_jiffies
+ (GC_SLEEP_MS));
+ else if (ret)
pr_warn("gc failed!");
} while (ret && !test_bit(CACHE_SET_IO_DISABLE, &c->flags));
@@ -1834,8 +1873,14 @@ static int bch_btree_check_recurse(struct btree *b, struct btree_op *op)
do {
k = bch_btree_iter_next_filter(&iter, &b->keys,
bch_ptr_bad);
- if (k)
+ if (k) {
btree_node_prefetch(b, k);
+ /*
+ * initiallize c->gc_stats.nodes
+ * for incremental GC
+ */
+ b->c->gc_stats.nodes++;
+ }
if (p)
ret = btree(check_recurse, p, b, op);