btrfs: trimming some start_transaction() code away
Just call kmem_cache_zalloc() instead of calling kmem_cache_alloc().
We're just initializing most fields to 0, false and NULL later on
_anyway_, so to make the code mode readable and potentially gain
a bit of performance (completely untested claim), we should fill our
btrfs_trans_handle with zeros on allocation then just initialize
those five remaining fields (not counting the list_heads) as normal.
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index a5b0644..c191606 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -502,7 +502,7 @@
goto reserve_fail;
}
again:
- h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
+ h = kmem_cache_zalloc(btrfs_trans_handle_cachep, GFP_NOFS);
if (!h) {
ret = -ENOMEM;
goto alloc_fail;
@@ -543,23 +543,10 @@
h->transid = cur_trans->transid;
h->transaction = cur_trans;
- h->blocks_used = 0;
- h->bytes_reserved = 0;
- h->chunk_bytes_reserved = 0;
h->root = root;
- h->delayed_ref_updates = 0;
h->use_count = 1;
- h->adding_csums = 0;
- h->block_rsv = NULL;
- h->orig_rsv = NULL;
- h->aborted = 0;
- h->qgroup_reserved = 0;
- h->delayed_ref_elem.seq = 0;
h->type = type;
- h->allocating_chunk = false;
h->can_flush_pending_bgs = true;
- h->reloc_reserved = false;
- h->sync = false;
INIT_LIST_HEAD(&h->qgroup_ref_list);
INIT_LIST_HEAD(&h->new_bgs);
INIT_LIST_HEAD(&h->ordered);