On Wed, Dec 12, 2018 at 12:26 AM Stephen R. van den Berg <srb@xxxxxxx> wrote: > > Chris Murphy wrote: > >Also, what scheduler are you using? And do you get different results > >with a different one (better or worse)? > > I'm using CFQ, and I don't think I ever tried a different one. > But, btrfs should be compatible with all schedulers. Sure but there are some workloads we know where CFQ can cause or exacerbate problems with some storage stacks, and other schedulers exist to deal with those workloads better. So the question is whether the problem is made worse or better by trying another scheduler. It might have no effect. And it might just flat out be a Btrfs bug, but I'm doing send and receive on far more meager hardware with much less RAM and haven't run into problems. But yeah, one of the developers might have more to say about it once sysrq+w output is available, which should expose what's stuck or busy. -- Chris Murphy
