On 05/14/2013 12:59 PM, Yinghai Lu wrote: > On Tue, May 14, 2013 at 12:45 PM, Alexander Duyck > <alexander.h.duyck@xxxxxxxxx> wrote: >> On 05/14/2013 11:44 AM, Yinghai Lu wrote: >>> On Tue, May 14, 2013 at 9:00 AM, Alexander Duyck >>> <alexander.h.duyck@xxxxxxxxx> wrote: >>>> I'm sorry, but what is the point of this patch? With device assignment >>>> it is always possible to have VFs loaded and the PF driver unloaded >>>> since you cannot remove the VFs if they are assigned to a VM. >>> unload PF driver will not call pci_disable_sriov? >> You cannot call pci_disable_sriov because you will panic all of the >> guests that have devices assigned. > ixgbe_remove did call pci_disable_sriov... > > for guest panic, that is another problem. > just like you pci passthrough with real pci device and hotremove the > card in host. > > ... I suggest you take another look. In ixgbe_disable_sriov, which is the function that is called we do a check for assigned VFs. If they are assigned then we do not call pci_disable_sriov. > >> So how does your patch actually fix this problem? It seems like it is >> just avoiding it. > yes, until the first one is done. Avoiding the issue doesn't fix the underlying problem and instead you are likely just introducing more bugs as a result. >> From what I can tell your problem is originating in pci_call_probe. I >> believe it is calling work_on_cpu and that doesn't seem correct since >> the work should be taking place on a CPU already local to the PF. You >> might want to look there to see why you are trying to schedule work on a >> CPU which should be perfectly fine for you to already be doing your work on. > it always try to go with local cpu with same pxm. The problem is we really shouldn't be calling work_for_cpu in this case since we are already on the correct CPU. What probably should be happening is that pci_call_probe should be doing a check to see if the current CPU is already contained within the device node map and if so just call local_pci_probe directly. That way you can avoid deadlocking the system by trying to flush the CPU queue of the CPU you are currently on. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
