On Tue, 2025-04-08 at 10:09 -0700, Luis Chamberlain wrote: > On Tue, Apr 08, 2025 at 11:43:46AM -0400, James Bottomley wrote: [...] > > I've now done some extensive testing on loop nested filesystems > > with fio load on the upper. I've tried xfs on ext4 and ext4 on > > ext4. Hibernate/Resume has currently worked on these without a > > hitch (and the fio load burps a bit but then starts running at full > > speed within a few seconds). What I'm doing is a single round of > > hibernate/resume followed by a reboot. I'm relying on the fschecks > > to detect any filesystem corruption. I've also tried doing a couple > > of fresh starts of the hibernated image to check that we did > > correctly freeze the filesystems. > > > > The problems I've noticed are: > > > > 1. I'm using 9p to push host directories throught and that > > completely hangs after a resume. This is expected because the > > virtio server is out of sync, but it does indicate a need to > > address Jeff's question of what we should be doing for > > network > > filesystems (and is also the reason I have to reboot after > > resuming). > > 2. Top doesn't show any CPU activity after resume even though > > fio is > > definitely running. This seems to be a suspend issue and > > unrelated to filesystems, but I'll continue investigating. > > To be clear, on the fio run -- are you running fio *while* > suspend/resume cycle on XFS? Yes, that's why I said "the fio load burps a bit" (as in after resume) "but then starts running full speed after a few seconds". > That used to stall / break suspend resume. We may want to test dd > against a drive too, that will use the block device cache, and I > forget if we have a freeze/thaw for it. fio is running a read/write test, but I think all my caches are write through for safety (although I have verified that the device cache flush is sent as the last sequence of hibernate). Regards, James
