On Mon, May 06, 2019 at 05:52:48PM +0000, Marciniszyn, Mike wrote: > > > > My mistake. It's been a long while since I coded the stuff I did for > > memory reclaim pressure and I had my flag usage wrong in my memory. > > From the description you just gave, the original patch to add > > WQ_MEM_RECLAIM is ok. I probably still need to audit the ipoib usage > > though. > > > > Don't lose sight of the fact that the additional of the WQ_MEM_RECLAIM is to silence > a warning BECAUSE ipoib's workqueue is WQ_MEM_RECLAIM. This happens while > rdmavt/hfi1 is doing a cancel_work_sync() for the work item used by the QP's send engine > > The ipoib wq needs to be audited to see if it is in the data path for VM I/O. Well, it is doing unsafe memory allocations and other stuff, so it can't be RECLAIM. We should just delete them from IPoIB like Doug says. Before we get excited about IPoIB I'd love to hear how the netstack is supposed to handle reclaim as well ie when using NFS/etc. AFAIK the netstack code is not reclaim safe and can need to do things like allocate neighbour structures/etc to progress the dataplane. Jason
