From patchwork Thu Jul 24 03:37:10 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miao Xie X-Patchwork-Id: 4614371 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 2F1509FB16 for ; Thu, 24 Jul 2014 03:36:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 58861201BC for ; Thu, 24 Jul 2014 03:36:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6C23B201D3 for ; Thu, 24 Jul 2014 03:35:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758733AbaGXDfz (ORCPT ); Wed, 23 Jul 2014 23:35:55 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:4420 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1758707AbaGXDfj (ORCPT ); Wed, 23 Jul 2014 23:35:39 -0400 X-IronPort-AV: E=Sophos;i="5.00,931,1396972800"; d="scan'208";a="33711348" Received: from localhost (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 24 Jul 2014 11:32:50 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id s6O3ZZFK017397 for ; Thu, 24 Jul 2014 11:35:35 +0800 Received: from miao.fnst.cn.fujitsu.com (10.167.226.169) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Thu, 24 Jul 2014 11:35:47 +0800 From: Miao Xie To: Subject: [PATCH 05/10] Btrfs: make the device lock and its protected data in the same cacheline Date: Thu, 24 Jul 2014 11:37:10 +0800 Message-ID: <1406173035-29478-5-git-send-email-miaox@cn.fujitsu.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1406173035-29478-1-git-send-email-miaox@cn.fujitsu.com> References: <1406173035-29478-1-git-send-email-miaox@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.169] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The lock in btrfs_device structure was far away from its protected data, it would make CPU load the cache line twice when we accessed them, move them together. Signed-off-by: Miao Xie --- fs/btrfs/volumes.h | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 2aaa00c..6fcc8ea 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -36,30 +36,31 @@ struct btrfs_device { struct list_head dev_list; struct list_head dev_alloc_list; struct btrfs_fs_devices *fs_devices; + struct btrfs_root *dev_root; + struct rcu_string *name; + + u64 generation; + + spinlock_t io_lock ____cacheline_aligned; + int running_pending; /* regular prio bios */ struct btrfs_pending_bios pending_bios; /* WRITE_SYNC bios */ struct btrfs_pending_bios pending_sync_bios; - u64 generation; - int running_pending; + struct block_device *bdev; + + /* the mode sent to blkdev_get */ + fmode_t mode; + int writeable; int in_fs_metadata; int missing; int can_discard; int is_tgtdev_for_dev_replace; - spinlock_t io_lock; - /* the mode sent to blkdev_get */ - fmode_t mode; - - struct block_device *bdev; - - - struct rcu_string *name; - /* the internal btrfs device id */ u64 devid; @@ -83,7 +84,6 @@ struct btrfs_device { /* minimal io size for this device */ u32 sector_size; - /* physical drive uuid (or lvm uuid) */ u8 uuid[BTRFS_UUID_SIZE]; @@ -107,7 +107,6 @@ struct btrfs_device { struct radix_tree_root reada_zones; struct radix_tree_root reada_extents; - /* disk I/O failure stats. For detailed description refer to * enum btrfs_dev_stat_values in ioctl.h */ int dev_stats_valid;