On Tue, Feb 17, 2015 at 10:36:54AM -0500, Michael L. Semon wrote: > On 02/16/15 18:17, Dave Chinner wrote: > > On Mon, Feb 16, 2015 at 11:35:50AM -0600, Mark Tinguely wrote: > >> Thanks Michael, you don't need to hold your test box for me. I do > >> have a way to recreate these ABBA AGF buffer allocation deadlocks > >> and understand the whys and hows very well. I don't have a community > >> way to make a xfstest for it but I think your test is getting close. > > > > If you know what is causing them, then please explain how it occurs > > and how you think it needs to be fixed. Just telling us that you know > > something that we don't doesn't help us solve the problem. :( > > > > In general, the use of the args->firstblock is supposed to avoid the > > ABBA locking order issues with multiple allocations in the one > > transaction by preventing AG selection loops from looping back into > > AGs with a lower index than the first allocation that was made. > > > > So if you are seeing deadlocks, then it may be that we aren't > > following this constraint correctly in all locations.... > > Will this be a classic deadlock that will cause problems when trying to > kill processes and unmount filesystems? If so, then I was unable to use > generic/224 to trigger a deadlock. If not, then I'll need a better way > of looking at the problem. Yes, it will hang the filesystem. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
