From: jing zhang Subject: [PATCH] ext4: try fast merge operation in ext4_mb_free_metadata() Date: Wed, 24 Mar 2010 21:32:39 +0800 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: "Theodore Ts'o" , Andreas Dilger , Dave Kleikamp To: linux-ext4 Return-path: Received: from mail-yw0-f172.google.com ([209.85.211.172]:52580 "EHLO mail-yw0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756059Ab0CXNcl (ORCPT ); Wed, 24 Mar 2010 09:32:41 -0400 Received: by ywh2 with SMTP id 2so2852099ywh.33 for ; Wed, 24 Mar 2010 06:32:40 -0700 (PDT) Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Jing Zhang Date: Wed Mar 24 21:30:22 2010 There may exist fast path for merge if merge-able. Cc: Theodore Ts'o Cc: Andreas Dilger Cc: Dave Kleikamp Signed-off-by: Jing Zhang --- --- linux-2.6.32/fs/ext4/mballoc.c 2009-12-03 11:51:22.000000000 +0800 +++ ext4_mm_leak/mballoc7.c 2010-03-24 21:27:24.000000000 +0800 @@ -4385,6 +4385,24 @@ ext4_mb_free_metadata(handle_t *handle, } } + if (parent) { + /* let's try fast path */ + entry = rb_entry(parent, struct ext4_free_data, node); + if (n == &parent->rb_left) { + if (can_merge(new_entry, entry)) { + entry->start_blk = new_entry->start_blk; + entry->count += new_entry->count; + /* and info the caller that new_entry is + * not used yet. + */ + return 0; + } + } + else if (can_merge(entry, new_entry)) { + entry->count += new_entry->count; + return 0; + } + } rb_link_node(new_node, parent, n); rb_insert_color(new_node, &db->bb_free_root);