bcache: Fix/revamp tracepoints
The tracepoints were reworked to be more sensible, and fixed a null
pointer deref in one of the tracepoints.
Converted some of the pr_debug()s to tracepoints - this is partly a
performance optimization; it used to be that with DEBUG or
CONFIG_DYNAMIC_DEBUG pr_debug() was an empty macro; but at some point it
was changed to an empty inline function.
Some of the pr_debug() statements had rather expensive function calls as
part of the arguments, so this code was getting run unnecessarily even
on non debug kernels - in some fast paths, too.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index aaec186..218d486 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -223,8 +223,9 @@
struct closure cl;
struct bio *bio;
+ trace_bcache_btree_read(b);
+
closure_init_stack(&cl);
- pr_debug("%s", pbtree(b));
bio = bch_bbio_alloc(b->c);
bio->bi_rw = REQ_META|READ_SYNC;
@@ -234,7 +235,6 @@
bch_bio_map(bio, b->sets[0].data);
- trace_bcache_btree_read(bio);
bch_submit_bbio(bio, b->c, &b->key, 0);
closure_sync(&cl);
@@ -343,7 +343,6 @@
memcpy(page_address(bv->bv_page),
base + j * PAGE_SIZE, PAGE_SIZE);
- trace_bcache_btree_write(b->bio);
bch_submit_bbio(b->bio, b->c, &k.key, 0);
continue_at(cl, btree_node_write_done, NULL);
@@ -351,7 +350,6 @@
b->bio->bi_vcnt = 0;
bch_bio_map(b->bio, i);
- trace_bcache_btree_write(b->bio);
bch_submit_bbio(b->bio, b->c, &k.key, 0);
closure_sync(cl);
@@ -363,10 +361,13 @@
{
struct bset *i = b->sets[b->nsets].data;
+ trace_bcache_btree_write(b);
+
BUG_ON(current->bio_list);
BUG_ON(b->written >= btree_blocks(b));
BUG_ON(b->written && !i->keys);
BUG_ON(b->sets->data->seq != i->seq);
+ bch_check_key_order(b, i);
cancel_delayed_work(&b->work);
@@ -376,12 +377,8 @@
clear_bit(BTREE_NODE_dirty, &b->flags);
change_bit(BTREE_NODE_write_idx, &b->flags);
- bch_check_key_order(b, i);
-
do_btree_node_write(b);
- pr_debug("%s block %i keys %i", pbtree(b), b->written, i->keys);
-
b->written += set_blocks(i, b->c);
atomic_long_add(set_blocks(i, b->c) * b->c->sb.block_size,
&PTR_CACHE(b->c, &b->key, 0)->btree_sectors_written);
@@ -752,6 +749,8 @@
int ret = -ENOMEM;
struct btree *i;
+ trace_bcache_btree_cache_cannibalize(c);
+
if (!cl)
return ERR_PTR(-ENOMEM);
@@ -770,7 +769,6 @@
return ERR_PTR(-EAGAIN);
}
- /* XXX: tracepoint */
c->try_harder = cl;
c->try_harder_start = local_clock();
retry:
@@ -956,13 +954,14 @@
{
unsigned i;
+ trace_bcache_btree_node_free(b);
+
/*
* The BUG_ON() in btree_node_get() implies that we must have a write
* lock on parent to free or even invalidate a node
*/
BUG_ON(op->lock <= b->level);
BUG_ON(b == b->c->root);
- pr_debug("bucket %s", pbtree(b));
if (btree_node_dirty(b))
btree_complete_write(b, btree_current_write(b));
@@ -1012,12 +1011,16 @@
bch_bset_init_next(b);
mutex_unlock(&c->bucket_lock);
+
+ trace_bcache_btree_node_alloc(b);
return b;
err_free:
bch_bucket_free(c, &k.key);
__bkey_put(c, &k.key);
err:
mutex_unlock(&c->bucket_lock);
+
+ trace_bcache_btree_node_alloc_fail(b);
return b;
}
@@ -1254,7 +1257,7 @@
btree_node_free(r->b, op);
up_write(&r->b->lock);
- pr_debug("coalesced %u nodes", nodes);
+ trace_bcache_btree_gc_coalesce(nodes);
gc->nodes--;
nodes--;
@@ -1479,8 +1482,7 @@
struct btree_op op;
uint64_t start_time = local_clock();
- trace_bcache_gc_start(c->sb.set_uuid);
- blktrace_msg_all(c, "Starting gc");
+ trace_bcache_gc_start(c);
memset(&stats, 0, sizeof(struct gc_stat));
closure_init_stack(&writes);
@@ -1496,9 +1498,7 @@
closure_sync(&writes);
if (ret) {
- blktrace_msg_all(c, "Stopped gc");
pr_warn("gc failed!");
-
continue_at(cl, bch_btree_gc, bch_gc_wq);
}
@@ -1519,8 +1519,7 @@
stats.in_use = (c->nbuckets - available) * 100 / c->nbuckets;
memcpy(&c->gc_stats, &stats, sizeof(struct gc_stat));
- blktrace_msg_all(c, "Finished gc");
- trace_bcache_gc_end(c->sb.set_uuid);
+ trace_bcache_gc_end(c);
continue_at(cl, bch_moving_gc, bch_gc_wq);
}
@@ -1901,12 +1900,11 @@
split = set_blocks(n1->sets[0].data, n1->c) > (btree_blocks(b) * 4) / 5;
- pr_debug("%ssplitting at %s keys %i", split ? "" : "not ",
- pbtree(b), n1->sets[0].data->keys);
-
if (split) {
unsigned keys = 0;
+ trace_bcache_btree_node_split(b, n1->sets[0].data->keys);
+
n2 = bch_btree_node_alloc(b->c, b->level, &op->cl);
if (IS_ERR(n2))
goto err_free1;
@@ -1941,8 +1939,11 @@
bch_keylist_add(&op->keys, &n2->key);
bch_btree_node_write(n2, &op->cl);
rw_unlock(true, n2);
- } else
+ } else {
+ trace_bcache_btree_node_compact(b, n1->sets[0].data->keys);
+
bch_btree_insert_keys(n1, op);
+ }
bch_keylist_add(&op->keys, &n1->key);
bch_btree_node_write(n1, &op->cl);
@@ -2117,6 +2118,8 @@
{
unsigned i;
+ trace_bcache_btree_set_root(b);
+
BUG_ON(!b->written);
for (i = 0; i < KEY_PTRS(&b->key); i++)
@@ -2130,7 +2133,6 @@
__bkey_put(b->c, &b->key);
bch_journal_meta(b->c, NULL);
- pr_debug("%s for %pf", pbtree(b), __builtin_return_address(0));
}
/* Cache lookup */
@@ -2216,7 +2218,6 @@
n->bi_end_io = bch_cache_read_endio;
n->bi_private = &s->cl;
- trace_bcache_cache_hit(n);
__bch_submit_bbio(n, b->c);
}