On Mon, May 06, 2019 at 03:16:10PM -0300, Jason Gunthorpe wrote: > 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. Please don't. > > 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
