From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:1352 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751574Ab2GYF7l (ORCPT ); Wed, 25 Jul 2012 01:59:41 -0400 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q6P5xWGw005253 for ; Wed, 25 Jul 2012 13:59:39 +0800 From: Liu Bo To: Subject: [PATCH 1/6 v3][RFC] Btrfs: merge adjacent states as much as possible Date: Wed, 25 Jul 2012 13:58:37 +0800 Message-Id: <1343195922-31405-2-git-send-email-liubo2009@cn.fujitsu.com> In-Reply-To: <1343195922-31405-1-git-send-email-liubo2009@cn.fujitsu.com> References: <1343195922-31405-1-git-send-email-liubo2009@cn.fujitsu.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: In order to reduce write locks, we do merge_state as much as much as possible. Signed-off-by: Liu Bo --- fs/btrfs/extent_io.c | 47 +++++++++++++++++++++++++++-------------------- 1 files changed, 27 insertions(+), 20 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 01c21b6..1858d86 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -275,29 +275,36 @@ static void merge_state(struct extent_io_tree *tree, if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) return; - other_node = rb_prev(&state->rb_node); - if (other_node) { + while (1) { + other_node = rb_prev(&state->rb_node); + if (!other_node) + break; other = rb_entry(other_node, struct extent_state, rb_node); - if (other->end == state->start - 1 && - other->state == state->state) { - merge_cb(tree, state, other); - state->start = other->start; - other->tree = NULL; - rb_erase(&other->rb_node, &tree->state); - free_extent_state(other); - } + if (other->end != state->start - 1 || + other->state != state->state) + break; + + merge_cb(tree, state, other); + state->start = other->start; + other->tree = NULL; + rb_erase(&other->rb_node, &tree->state); + free_extent_state(other); } - other_node = rb_next(&state->rb_node); - if (other_node) { + + while (1) { + other_node = rb_next(&state->rb_node); + if (!other_node) + break; other = rb_entry(other_node, struct extent_state, rb_node); - if (other->start == state->end + 1 && - other->state == state->state) { - merge_cb(tree, state, other); - state->end = other->end; - other->tree = NULL; - rb_erase(&other->rb_node, &tree->state); - free_extent_state(other); - } + if (other->start != state->end + 1 || + other->state != state->state) + break; + + merge_cb(tree, state, other); + state->end = other->end; + other->tree = NULL; + rb_erase(&other->rb_node, &tree->state); + free_extent_state(other); } } -- 1.6.5.2