From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 08 Apr 2008 21:10:55 -0700 (PDT) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with SMTP id m394AdrK011496 for ; Tue, 8 Apr 2008 21:10:42 -0700 Date: Wed, 9 Apr 2008 14:11:13 +1000 From: David Chinner Subject: [patch] Re: Does XFS prevent disk spindown? Message-ID: <20080409041113.GC108924158@sgi.com> References: <20080401003005.GJ103491721@sgi.com> <47F1CF6D.2040103@sandeen.net> <47F9735E.8020900@sgi.com> <20080407215855.GE108924158@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Thor Kristoffersen Cc: David Chinner , Timothy Shimmin , xfs@oss.sgi.com On Tue, Apr 08, 2008 at 07:53:13AM +0200, Thor Kristoffersen wrote: > David Chinner writes: > >> > What does 'xfs_logprint -t' show in these "idle" states > >> > after these writes? > >> > >> xfs_logprint produces output like the one shown below, so it does indeed > >> look like it's writing to the journal. But why should it need to keep > >> writing to the journal when there have been no updates to any files on that > >> partition recently? > > > > Are you using lazy-count=1? (i.e. output of 'xfs_info ', please). > > Looks like I am: > > meta-data=/dev/sda3 isize=256 agcount=4, agsize=42676171 blks > = sectsz=512 attr=2 > data = bsize=4096 blocks=170704681, imaxpct=25 > = sunit=0 swidth=0 blks > naming =version 2 bsize=4096 > log =internal bsize=4096 blocks=32768, version=2 > = sectsz=512 sunit=0 blks, lazy-count=1 > realtime =none extsz=4096 blocks=0, rtextents=0 > > Is that what's causing it? I have never specified any lazy-count option > when I created or mounted the filesystem. I didn't even know it existed. Introduced in 2.6.22, and recently was made the default mkfs config. Try the patch below. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group Remove periodic logging of in-core superblock counters. xfssyncd triggers the logging of superblock counters every 30s if the filesystem is made with lazy-count=1. This will prevent disks from idling and spinning down as there will be a log write every 30s. With the way counter recovery works for lazy-count=1, this code is unnecessary and provides no real benefit, so just remove it. Signed-off-by: Dave Chinner --- fs/xfs/linux-2.6/xfs_super.c | 3 +-- fs/xfs/linux-2.6/xfs_vfs.h | 1 - fs/xfs/xfs_vfsops.c | 10 ---------- 3 files changed, 1 insertion(+), 13 deletions(-) Index: 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_super.c =================================================================== --- 2.6.x-xfs-new.orig/fs/xfs/linux-2.6/xfs_super.c 2008-04-02 09:25:11.000000000 +1000 +++ 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_super.c 2008-04-02 10:02:25.391897032 +1000 @@ -1028,8 +1028,7 @@ xfs_sync_worker( int error; if (!(mp->m_flags & XFS_MOUNT_RDONLY)) - error = xfs_sync(mp, SYNC_FSDATA | SYNC_BDFLUSH | SYNC_ATTR | - SYNC_REFCACHE | SYNC_SUPER); + error = xfs_sync(mp, SYNC_FSDATA | SYNC_BDFLUSH | SYNC_ATTR); mp->m_sync_seq++; wake_up(&mp->m_wait_single_sync_task); } Index: 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_vfs.h =================================================================== --- 2.6.x-xfs-new.orig/fs/xfs/linux-2.6/xfs_vfs.h 2007-08-24 22:25:22.000000000 +1000 +++ 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_vfs.h 2008-04-02 10:02:52.596414152 +1000 @@ -49,7 +49,6 @@ typedef struct bhv_vfs_sync_work { #define SYNC_REFCACHE 0x0040 /* prune some of the nfs ref cache */ #define SYNC_REMOUNT 0x0080 /* remount readonly, no dummy LRs */ #define SYNC_IOWAIT 0x0100 /* wait for all I/O to complete */ -#define SYNC_SUPER 0x0200 /* flush superblock to disk */ /* * When remounting a filesystem read-only or freezing the filesystem, Index: 2.6.x-xfs-new/fs/xfs/xfs_vfsops.c =================================================================== --- 2.6.x-xfs-new.orig/fs/xfs/xfs_vfsops.c 2008-04-02 09:00:55.000000000 +1000 +++ 2.6.x-xfs-new/fs/xfs/xfs_vfsops.c 2008-04-02 10:01:35.534280170 +1000 @@ -1334,18 +1334,8 @@ xfs_syncsub( } /* - * If asked, update the disk superblock with incore counter values if we - * are using non-persistent counters so that they don't get too far out - * of sync if we crash or get a forced shutdown. We don't want to force - * this to disk, just get a transaction into the iclogs.... - */ - if (flags & SYNC_SUPER) - xfs_log_sbcount(mp, 0); - - /* * Now check to see if the log needs a "dummy" transaction. */ - if (!(flags & SYNC_REMOUNT) && xfs_log_need_covered(mp)) { xfs_trans_t *tp; xfs_inode_t *ip;