Btrfs: simpler and more efficient cleanup of a log tree's extent io tree
PATCH 1/1 Btrfs: simpler and more efficient cleanup of a log tree's extent io tree
From: Filipe Manana <[email protected]>
We currently are in a loop finding each range (corresponding to a btree node/leaf) in a log root's extent io tree and then clean it up. This is a waste of time since we are traversing the extent io tree's rb_tree more times then needed (one for a range lookup and another for cleaning it up) without any good reason.
We free the log trees when we are in the critical section of a transaction commit (the transaction state is set to TRANS_STATE_COMMIT_DOING), so it's of great convenience to do everything as fast as possible in order to reduce the time we block other tasks from starting a new transaction.
So fix this by traversing the extent io tree once and cleaning up all its records in one go while traversing it.
--- fs/btrfs/tree-log.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-)
fs/btrfs/tree-log.c +2 -14
@@ -3204,8 +3204,6 @@ static void free_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *log) {int ret; -u64 start; -u64 end;struct walk_control wc = { .free =1 , .process_func = process_one_buffer
@@ -3216,18 +3214,8 @@ static void free_log_tree(struct btrfs_trans_handle *trans,if (ret)btrfs_abort_transaction (trans, ret); -while (1 ) { - ret =find_first_extent_bit (&log->dirty_log_pages, -0 , &start, &end, -EXTENT_DIRTY |EXTENT_NEW |EXTENT_NEED_WAIT , -NULL ); -if (ret) -break ; - -clear_extent_bits (&log->dirty_log_pages, start, end, -EXTENT_DIRTY |EXTENT_NEW |EXTENT_NEED_WAIT ); - } - +clear_extent_bits (&log->dirty_log_pages,0 , (u64)-1 , +EXTENT_DIRTY |EXTENT_NEW |EXTENT_NEED_WAIT );free_extent_buffer (log->node);kfree (log); }
Signature · 1 line
2.11.0
Quoted 13 lines · On 9.11.18 г. 12:43 ч., [email protected] wrote:
From: Filipe Manana <[email protected]>
We currently are in a loop finding each range (corresponding to a btree node/leaf) in a log root's extent io tree and then clean it up. This is a waste of time since we are traversing the extent io tree's
rb_treemore times then needed (one for a range lookup and another for cleaning it up) without any good reason.We free the log trees when we are in the critical section of a transaction commit (the transaction state is set to
TRANS_STATE_COMMIT_DOING), so it's of great convenience to do everything as fast as possible in order to reduce the time we block other tasks from starting a new transaction.
Quoted 4 lines
So fix this by traversing the extent io tree once and cleaning up all its records in one go while traversing it.
Signed-off-by Filipe Manana <[email protected]>
Quoted 39 lines
--- fs/btrfs/tree-log.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-)fs/btrfs/tree-log.c +2
-14@@ -3204,8 +3204,6 @@ static void free_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *log) {int ret; -u64 start; -u64 end;struct walk_control wc = { .free =1 , .process_func = process_one_buffer@@ -3216,18 +3214,8 @@ static void free_log_tree(struct btrfs_trans_handle *trans,if (ret)btrfs_abort_transaction (trans, ret); -while (1 ) { - ret =find_first_extent_bit (&log->dirty_log_pages, -0 , &start, &end, -EXTENT_DIRTY |EXTENT_NEW |EXTENT_NEED_WAIT , -NULL ); -if (ret) -break ; - -clear_extent_bits (&log->dirty_log_pages, start, end, -EXTENT_DIRTY |EXTENT_NEW |EXTENT_NEED_WAIT ); - } - +clear_extent_bits (&log->dirty_log_pages,0 , (u64)-1 , +EXTENT_DIRTY |EXTENT_NEW |EXTENT_NEED_WAIT );free_extent_buffer (log->node);kfree (log); }
Quoted 13 lines · On Fri, Nov 09, 2018 at 10:43:08AM +0000, [email protected] wrote:
From: Filipe Manana <[email protected]>
We currently are in a loop finding each range (corresponding to a btree node/leaf) in a log root's extent io tree and then clean it up. This is a waste of time since we are traversing the extent io tree's
rb_treemore times then needed (one for a range lookup and another for cleaning it up) without any good reason.We free the log trees when we are in the critical section of a transaction commit (the transaction state is set to
TRANS_STATE_COMMIT_DOING), so it's of great convenience to do everything as fast as possible in order to reduce the time we block other tasks from starting a new transaction.
Quoted 4 lines
So fix this by traversing the extent io tree once and cleaning up all its records in one go while traversing it.
Signed-off-by Filipe Manana <[email protected]>
Sheesh
Thanks,
Josef
Quoted 13 lines · On Fri, Nov 09, 2018 at 10:43:08AM +0000, [email protected] wrote:
From: Filipe Manana <[email protected]>
We currently are in a loop finding each range (corresponding to a btree node/leaf) in a log root's extent io tree and then clean it up. This is a waste of time since we are traversing the extent io tree's
rb_treemore times then needed (one for a range lookup and another for cleaning it up) without any good reason.We free the log trees when we are in the critical section of a transaction commit (the transaction state is set to
TRANS_STATE_COMMIT_DOING), so it's of great convenience to do everything as fast as possible in order to reduce the time we block other tasks from starting a new transaction.
Quoted 4 lines
So fix this by traversing the extent io tree once and cleaning up all its records in one go while traversing it.
Signed-off-by Filipe Manana <[email protected]>
Added to misc-next, thanks.