On 02/17/15 19:48, Dave Chinner wrote: > 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. Thanks. I'll try again tonight. Last night's attempt was a combination of fio, fsstress, and a shell loop of xfs_io's fcollapse command, all at once on an SSD. At the end of the night, XFS was laughing at me. Therefore, I added the same test on the 3-partition RAID-0 side. This morning, XFS is still laughing at me, but the RAID-0 test is still running. Thanks! Michael _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
