[PATCH for-next v7 0/5] fixed-buffer for uring-cmd/passthru

Kanchan Joshi
2022-09-09T10:31:50Z

Currently uring-cmd lacks the ability to leverage the pre-registered
buffers. This series adds that support in uring-cmd, and plumbs
nvme passthrough to work with it.

Using registered-buffers showed IOPS hike from 1.9M to 2.2M in my tests.

Patch 1, 3, 4 = prep
Patch 2 = expand io_uring command to use registered-buffers
Patch 5 = expand nvme passthrough to use registered-buffers

Changes since v6:
- Patch 1: fix warning for io_uring_cmd_import_fixed (robot)
-
Changes since v5:
- Patch 4: newly addd, to split a nvme function into two
- Patch 3: folded cleanups in bio_map_user_iov (Chaitanya, Pankaj)
- Rebase to latest for-next

Changes since v4:
- Patch 1, 2: folded all review comments of Jens

Changes since v3:
- uring_cmd_flags, change from u16 to u32 (Jens)
- patch 3, add another helper to reduce code-duplication (Jens)

Changes since v2:
- Kill the new opcode, add a flag instead (Pavel)
- Fix standalone build issue with patch 1 (Pavel)

Changes since v1:
- Fix a naming issue for an exported helper

Anuj Gupta (2):
io_uring: add io_uring_cmd_import_fixed
io_uring: introduce fixed buffer support for io_uring_cmd

Kanchan Joshi (3):
nvme: refactor nvme_alloc_user_request
block: add helper to map bvec iterator for passthrough
nvme: wire up fixed buffer support for nvme passthrough

block/blk-map.c | 87 ++++++++++++++++++++---
drivers/nvme/host/ioctl.c | 126 +++++++++++++++++++++-------------
include/linux/blk-mq.h | 1 +
include/linux/io_uring.h | 10 ++-
include/uapi/linux/io_uring.h | 9 +++
io_uring/uring_cmd.c | 26 ++++++-
6 files changed, 199 insertions(+), 60 deletions(-)

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2.25.1