diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 94ce79f..b13f1fb 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -34,6 +34,8 @@ #include "locking.h" #include "free-space-cache.h" +#undef SCRAMBLE_DELAYED_REFS + /* * control flags for do_chunk_alloc's force field * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk @@ -2364,6 +2366,49 @@ static void wait_for_more_refs(struct btrfs_fs_info *fs_info, spin_lock(&delayed_refs->lock); } +#ifdef SCRAMBLE_DELAYED_REFS +/* + * Normally delayed refs get processed in ascending bytenr order. This + * correlates in most cases to the order added. To expose dependencies on this + * order, we start to process the tree in the middle instead of the beginning + */ +static u64 find_middle(struct rb_root *root) +{ + struct rb_node *n = root->rb_node; + struct btrfs_delayed_ref_node *entry; + int alt = 1; + u64 middle; + u64 first = 0, last = 0; + + n = rb_first(root); + if (n) { + entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); + first = entry->bytenr; + } + n = rb_last(root); + if (n) { + entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); + last = entry->bytenr; + } + n = root->rb_node; + + while (n) { + entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); + WARN_ON(!entry->in_tree); + + middle = entry->bytenr; + + if (alt) + n = n->rb_left; + else + n = n->rb_right; + + alt = 1 - alt; + } + return middle; +} +#endif + /* * this starts processing the delayed reference count updates and * extent insertions we have queued up so far. count can be @@ -2406,6 +2451,10 @@ again: consider_waiting = 0; spin_lock(&delayed_refs->lock); +#ifdef SCRAMBLE_DELAYED_REFS + delayed_refs->run_delayed_start = find_middle(&delayed_refs->root); +#endif + if (count == 0) { count = delayed_refs->num_entries * 2; run_most = 1; |
