> -----Original Message----- > From: Jason Gunthorpe <jgg@xxxxxxxx> > Sent: Tuesday, May 19, 2020 8:27 PM > To: Dalessandro, Dennis <dennis.dalessandro@xxxxxxxxx> > Cc: dledford@xxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; Marciniszyn, Mike > <mike.marciniszyn@xxxxxxxxx>; stable@xxxxxxxxxxxxxxx; Wan, Kaike > <kaike.wan@xxxxxxxxx> > Subject: Re: [PATCH for-rc or next 1/3] IB/hfi1: Do not destroy hfi1_wq when > the device is shut down > > On Mon, May 11, 2020 at 11:13:15PM -0400, Dennis Dalessandro wrote: > > From: Kaike Wan <kaike.wan@xxxxxxxxx> > > > > The workqueue hfi1_wq is destroyed in function shutdown_device(), > > which is called by either shutdown_one() or remove_one(). The function > > shutdown_one() is called when the kernel is rebooted while > > remove_one() is called when the hfi1 driver is unloaded. When the > > kernel is rebooted, hfi1_wq is destroyed while all qps are still > > active, leading to a kernel crash: > > AFAIK the purpose of shutdown is to stop all in progress DMAs. > > If devices are wildly doing DMA during the shutdown process then all manner > of things can fail, including kexecing into another kernel. > > Do you achive that with these shutdown handlers? We did try to shut down the hardware and will address some software issues in next revision. > > It does make sense that the work queue would not be destroyed in > shutdown, but I'm surprised it doesn't flush it? Will do. Kaike
