From: Alexandru Moise <00moses.alexander00@gmail.com> Date: Thu, 27 Aug 2015 23:53:45 +0000 (+0000) Subject: btrfs: trimming some start_transaction() code away X-Git-Tag: firefly_0821_release~176^2~545^2~70^2~16 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f2f767e7345dfe56102d6809f647ba38a238f718;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> Signed-off-by: David Sterba --- diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index a5b06442f0bf..c1916067b799 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -502,7 +502,7 @@ start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type, 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 @@ again: 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);