On Mon, May 12, 2014 at 8:46 PM, Dave Chinner wrote: > On Mon, May 12, 2014 at 06:29:28PM -0700, Austin Schuh wrote: >> On Wed, Mar 5, 2014 at 4:53 PM, Austin Schuh wrote: >> > Hi Dave, >> > >> > On Wed, Mar 5, 2014 at 3:35 PM, Dave Chinner wrote: >> >> On Wed, Mar 05, 2014 at 03:08:16PM -0800, Austin Schuh wrote: >> >>> Howdy, >> >>> >> >>> I'm running a config_preempt_rt patched version of the 3.10.11 kernel, >> >>> and I'm seeing a couple lockups and crashes which I think are related >> >>> to XFS. >> >> >> >> I think they ar emore likely related to RT issues.... >> >> >> > >> > That very well may be true. >> > >> >> Your usb device has disconnected and gone down the device >> >> removal/invalidate partition route. and it's trying to flush the >> >> device, which is stuck on IO completion which is stuck waiting for >> >> the device error handling to error them out. >> >> >> >> So, this is a block device problem error handling problem caused by >> >> device unplug getting stuck because it's decided to ask the >> >> filesystem to complete operations that can't be completed until the >> >> device error handling progress far enough to error out the IOs that >> >> the filesystem is waiting for completion on. >> >> >> >> Cheers, >> >> >> >> Dave. >> >> -- >> >> Dave Chinner >> >> david@fromorbit.com >> >> I had the issue reproduce itself today with just the main SSD >> installed. This was on a new machine that was built this morning. >> There is a lot less going on in this trace than the previous one. > > The three blocked threads: > > 1. kworker running IO completion waiting on an inode lock, > holding locked pages. > 2. kworker running writeback flusher work waiting for a page lock > 3. direct flush work waiting for allocation, holding page > locks and the inode lock. > > What's the kworker thread running the allocation work doing? > > You might need to run `echo w > proc-sysrq-trigger` to get this > information... I was able to reproduce the lockup. I ran `echo w > /proc/sysrq-trigger` per your suggestion. I don't know how to figure out what the kworker thread is doing, but I'll happily do it if you can give me some guidance.