Re: Enabling peer to peer device transactions for PCIe devices
From: Logan Gunthorpe
Date: Mon Dec 05 2016 - 14:59:49 EST
On 05/12/16 12:46 PM, Jason Gunthorpe wrote:
NVMe might have to deal with pci-e hot-unplug, which is a similar
problem-class to the GPU case..
Sure, but if the NVMe device gets hot-unplugged it means that all the
CMB mappings are useless and need to be torn down. This probably means
killing any process that has mappings open.
In any event the allocator still needs to track which regions are in
use and be able to hook 'free' from userspace. That does suggest it
should be integrated into the nvme driver and not a bolt on driver..
Yup, that's correct. And yes, I've never suggested this to be a bolt on
driver -- I always expected for it to get integrated into the nvme
driver. (iopmem was not meant for this.)
Logan