On Fri, Jun 07, 2002 at 08:35:44AM -0700, Dale Stephenson wrote: > device-mapper (LVM2) uses (with VFS enhancement) the very same > fsync_dev_lockfs() and unlockfs() calls. However, the COW activity is not > handled through brw_kiovec(), instead being transferred to device-mapper's > kcopyd. I haven't worked with LVM2 yet, so it's certainly possible that > kcopyd allieviates the pressure on kupdated. But in theory I would expect > it to be susceptible to the same file system deadlocks experienced by LVM1. I'm not sure what this kupdated interaction that you mention could be. Both brw_kiovec and kcopyd stay well away from both the filesystem and the buffer cache. > 2) I'm still seeing an occasional xfs_freeze deadlock. > xfs_unmountfs_writesb() (from xfs_freeze) and kupdated get stuck on separate > pagebuf locks. It occurs with multiple snapshots and streaming writes to > the snapshot source over both samba and nfs. Which kernel are you using ? I've found that 2.4.18 can be easily persuaded to deadlock by having two processes making GFP_NOIO requests for memory whilst the system is short of free memory. 2.4.19-pre9 works fine. - Joe _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
