On Fri, 1 Feb 2019, Hannes Reinecke wrote: > Thing is, if we have _managed_ CPU hotplug (ie if the hardware provides some > means of quiescing the CPU before hotplug) then the whole thing is trivial; > disable SQ and wait for all outstanding commands to complete. > Then trivially all requests are completed and the issue is resolved. > Even with todays infrastructure. > > And I'm not sure if we can handle surprise CPU hotplug at all, given all the > possible race conditions. > But then I might be wrong. The kernel would completely fall apart when a CPU would vanish by surprise, i.e. uncontrolled by the kernel. Then the SCSI driver exploding would be the least of our problems. Thanks, tglx