On Thu, 21 Aug 2008, Szabolcs Szakacsits wrote: > On Thu, 21 Aug 2008, Dave Chinner wrote: > > On Thu, Aug 21, 2008 at 04:04:18PM +1000, Dave Chinner wrote: > > > > > > One thing I just found out - my old *laptop* is 4-5x faster than the > > > 10krpm scsi disk behind an old cciss raid controller. I'm wondering > > > if the long delays in dispatch is caused by an interaction with CTQ > > > but I can't change it on the cciss raid controllers. Are you using > > > ctq/ncq on your machine? > > It's a laptop and has NCQ. It makes no difference if NCQ is enabled or > disabled. The problem seems to be XFS only. The 'nobarrier' mount option made a big improvement: MB/s Runtime (s) ----- ----------- btrfs unstable 17.09 572 ext3 13.24 877 btrfs 0.16 12.33 793 nilfs2 2nd+ runs 11.29 674 ntfs-3g 8.55 865 reiserfs 8.38 966 xfs nobarrier 7.89 949 nilfs2 1st run 4.95 3800 xfs 1.88 3901 Szaka -- NTFS-3G: http://ntfs-3g.org -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html