Re: [PATCH v4 00/14] Copy Offload in NVMe Fabrics with P2P PCI Memory

Bjorn Helgaas
2018-05-07T23:23:46Z

On Mon, Apr 23, 2018 at 05:30:32PM -0600, Logan Gunthorpe wrote:
> Hi Everyone,
>
> Here's v4 of our series to introduce P2P based copy offload to NVMe
> fabrics. This version has been rebased onto v4.17-rc2. A git repo
> is here:
>
> https://github.com/sbates130272/linux-p2pmem pci-p2p-v4
> ...

> Logan Gunthorpe (14):
> PCI/P2PDMA: Support peer-to-peer memory
> PCI/P2PDMA: Add sysfs group to display p2pmem stats
> PCI/P2PDMA: Add PCI p2pmem dma mappings to adjust the bus offset
> PCI/P2PDMA: Clear ACS P2P flags for all devices behind switches
> docs-rst: Add a new directory for PCI documentation
> PCI/P2PDMA: Add P2P DMA driver writer's documentation
> block: Introduce PCI P2P flags for request and request queue
> IB/core: Ensure we map P2P memory correctly in
> rdma_rw_ctx_[init|destroy]()
> nvme-pci: Use PCI p2pmem subsystem to manage the CMB
> nvme-pci: Add support for P2P memory in requests
> nvme-pci: Add a quirk for a pseudo CMB
> nvmet: Introduce helper functions to allocate and free request SGLs
> nvmet-rdma: Use new SGL alloc/free helper for requests
> nvmet: Optionally use PCI P2P memory
>
> Documentation/ABI/testing/sysfs-bus-pci | 25 +
> Documentation/PCI/index.rst | 14 +
> Documentation/driver-api/index.rst | 2 +-
> Documentation/driver-api/pci/index.rst | 20 +
> Documentation/driver-api/pci/p2pdma.rst | 166 ++++++
> Documentation/driver-api/{ => pci}/pci.rst | 0
> Documentation/index.rst | 3 +-
> block/blk-core.c | 3 +
> drivers/infiniband/core/rw.c | 13 +-
> drivers/nvme/host/core.c | 4 +
> drivers/nvme/host/nvme.h | 8 +
> drivers/nvme/host/pci.c | 118 +++--
> drivers/nvme/target/configfs.c | 67 +++
> drivers/nvme/target/core.c | 143 ++++-
> drivers/nvme/target/io-cmd.c | 3 +
> drivers/nvme/target/nvmet.h | 15 +
> drivers/nvme/target/rdma.c | 22 +-
> drivers/pci/Kconfig | 26 +
> drivers/pci/Makefile | 1 +
> drivers/pci/p2pdma.c | 814 +++++++++++++++++++++++++++++
> drivers/pci/pci.c | 6 +
> include/linux/blk_types.h | 18 +-
> include/linux/blkdev.h | 3 +
> include/linux/memremap.h | 19 +
> include/linux/pci-p2pdma.h | 118 +++++
> include/linux/pci.h | 4 +
> 26 files changed, 1579 insertions(+), 56 deletions(-)
> create mode 100644 Documentation/PCI/index.rst
> create mode 100644 Documentation/driver-api/pci/index.rst
> create mode 100644 Documentation/driver-api/pci/p2pdma.rst
> rename Documentation/driver-api/{ => pci}/pci.rst (100%)
> create mode 100644 drivers/pci/p2pdma.c
> create mode 100644 include/linux/pci-p2pdma.h

How do you envison merging this? There's a big chunk in drivers/pci, but
really no opportunity for conflicts there, and there's significant stuff in
block and nvme that I don't really want to merge.

If Alex is OK with the ACS situation, I can ack the PCI parts and you could
merge it elsewhere?

Bjorn