From fb235dc06fac9eaa4408ade9c8b20d45d63c89b7 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Wed, 15 Feb 2017 10:43:03 +0800 Subject: btrfs: qgroup: Move half of the qgroup accounting time out of commit trans Just as Filipe pointed out, the most time consuming parts of qgroup are btrfs_qgroup_account_extents() and btrfs_qgroup_prepare_account_extents(). Which both call btrfs_find_all_roots() to get old_roots and new_roots ulist. What makes things worse is, we're calling that expensive btrfs_find_all_roots() at transaction committing time with TRANS_STATE_COMMIT_DOING, which will blocks all incoming transaction. Such behavior is necessary for @new_roots search as current btrfs_find_all_roots() can't do it correctly so we do call it just before switch commit roots. However for @old_roots search, it's not necessary as such search is based on commit_root, so it will always be correct and we can move it out of transaction committing. This patch moves the @old_roots search part out of commit_transaction(), so in theory we can half the time qgroup time consumption at commit_transaction(). But please note that, this won't speedup qgroup overall, the total time consumption is still the same, just reduce the performance stall. Cc: Filipe Manana Signed-off-by: Qu Wenruo Reviewed-by: Filipe Manana Signed-off-by: David Sterba --- fs/btrfs/delayed-ref.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'fs/btrfs/delayed-ref.c') diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index a1b9ef2dfc4a..6eb80952efb3 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -550,13 +550,14 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_node *ref, struct btrfs_qgroup_extent_record *qrecord, u64 bytenr, u64 num_bytes, u64 ref_root, u64 reserved, - int action, int is_data) + int action, int is_data, int *qrecord_inserted_ret) { struct btrfs_delayed_ref_head *existing; struct btrfs_delayed_ref_head *head_ref = NULL; struct btrfs_delayed_ref_root *delayed_refs; int count_mod = 1; int must_insert_reserved = 0; + int qrecord_inserted = 0; /* If reserved is provided, it must be a data extent. */ BUG_ON(!is_data && reserved); @@ -623,6 +624,8 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, if(btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, qrecord)) kfree(qrecord); + else + qrecord_inserted = 1; } spin_lock_init(&head_ref->lock); @@ -650,6 +653,8 @@ add_delayed_ref_head(struct btrfs_fs_info *fs_info, atomic_inc(&delayed_refs->num_entries); trans->delayed_ref_updates++; } + if (qrecord_inserted_ret) + *qrecord_inserted_ret = qrecord_inserted; return head_ref; } @@ -779,6 +784,7 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_head *head_ref; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_qgroup_extent_record *record = NULL; + int qrecord_inserted; BUG_ON(extent_op && extent_op->is_data); ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS); @@ -806,12 +812,15 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info, * the spin lock */ head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record, - bytenr, num_bytes, 0, 0, action, 0); + bytenr, num_bytes, 0, 0, action, 0, + &qrecord_inserted); add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr, num_bytes, parent, ref_root, level, action); spin_unlock(&delayed_refs->lock); + if (qrecord_inserted) + return btrfs_qgroup_trace_extent_post(fs_info, record); return 0; free_head_ref: @@ -835,6 +844,7 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_head *head_ref; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_qgroup_extent_record *record = NULL; + int qrecord_inserted; ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS); if (!ref) @@ -868,13 +878,15 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, */ head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record, bytenr, num_bytes, ref_root, reserved, - action, 1); + action, 1, &qrecord_inserted); add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr, num_bytes, parent, ref_root, owner, offset, action); spin_unlock(&delayed_refs->lock); + if (qrecord_inserted) + return btrfs_qgroup_trace_extent_post(fs_info, record); return 0; } @@ -897,7 +909,7 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info, add_delayed_ref_head(fs_info, trans, &head_ref->node, NULL, bytenr, num_bytes, 0, 0, BTRFS_UPDATE_DELAYED_HEAD, - extent_op->is_data); + extent_op->is_data, NULL); spin_unlock(&delayed_refs->lock); return 0; -- cgit v1.2.3