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authorNikolay Borisov <nborisov@suse.com>2020-03-10 11:00:35 +0200
committerDavid Sterba <dsterba@suse.com>2020-03-23 17:01:55 +0100
commitdb161806dc5615a42893a1df7d803d12890699d9 (patch)
treefc1e73dc39b5788350afaec5e31a3dc3a185ccc5 /fs/btrfs/space-info.c
parentf8e6608180a31cc72a23b74969da428da236dbd1 (diff)
btrfs: account ticket size at add/delete time
Instead of iterating all pending tickets on the normal/priority list to sum their total size the cost can be amortized across ticket addition/ removal. This turns O(n) + O(m) (where n is the size of the normal list and m of the priority list) into O(1). This will mostly have effect in workloads that experience heavy flushing. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/space-info.c')
-rw-r--r--fs/btrfs/space-info.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 9cb511d8cd9d..8b0fe053a25d 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -389,6 +389,8 @@ again:
space_info,
ticket->bytes);
list_del_init(&ticket->list);
+ ASSERT(space_info->reclaim_size >= ticket->bytes);
+ space_info->reclaim_size -= ticket->bytes;
ticket->bytes = 0;
space_info->tickets_id++;
wake_up(&ticket->wait);
@@ -784,16 +786,12 @@ static inline u64
btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info)
{
- struct reserve_ticket *ticket;
u64 used;
u64 avail;
u64 expected;
- u64 to_reclaim = 0;
+ u64 to_reclaim = space_info->reclaim_size;
- list_for_each_entry(ticket, &space_info->tickets, list)
- to_reclaim += ticket->bytes;
- list_for_each_entry(ticket, &space_info->priority_tickets, list)
- to_reclaim += ticket->bytes;
+ lockdep_assert_held(&space_info->lock);
avail = calc_available_free_space(fs_info, space_info,
BTRFS_RESERVE_FLUSH_ALL);
@@ -1192,8 +1190,10 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
* the list and we will do our own flushing further down.
*/
if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
+ ASSERT(space_info->reclaim_size >= 0);
ticket.bytes = orig_bytes;
ticket.error = 0;
+ space_info->reclaim_size += ticket.bytes;
init_waitqueue_head(&ticket.wait);
if (flush == BTRFS_RESERVE_FLUSH_ALL) {
list_add_tail(&ticket.list, &space_info->tickets);