netdev - [RFC PATCH v4 0/3] io_uring: add napi busy polling support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221121172953.4030697-1-shr@devkernel.io>
Date:   Mon, 21 Nov 2022 09:29:50 -0800
From:   Stefan Roesch <shr@...kernel.io>
To:     kernel-team@...com
Cc:     shr@...kernel.io, axboe@...nel.dk, olivier@...llion01.com,
        netdev@...r.kernel.org, io-uring@...r.kernel.org, kuba@...nel.org
Subject: [RFC PATCH v4 0/3] io_uring: add napi busy polling support

This adds the napi busy polling support in io_uring.c. It adds a new
napi_list to the io_ring_ctx structure. This list contains the list of
napi_id's that are currently enabled for busy polling. This list is
used to determine which napi id's enabled busy polling.

io-uring allows specifying two parameters:
- busy poll timeout and
- prefer busy poll to call of io_napi_busy_loop()
This sets the above parameters for the ring. The settings are passed
with a new structure io_uring_napi.

There is also a corresponding liburing patch series, which enables this
feature. The name of the series is "liburing: add add api for napi busy
poll timeout". It also contains two programs to test the this.

Testing has shown that the round-trip times are reduced to 38us from
55us by enabling napi busy polling with a busy poll timeout of 100us.
More detailled results are part of the commit message of the first
patch.

Changes:
- V4:
  - Pass structure for napi config, instead of individual parameters
- V3:
  - Refreshed to 6.1-rc5
  - Added a new io-uring api for the prefer napi busy poll api and wire
    it to io_napi_busy_loop().
  - Removed the unregister (implemented as register)
  - Added more performance results to the first commit message.
- V2:
  - Add missing defines if CONFIG_NET_RX_BUSY_POLL is not defined
  - Changes signature of function io_napi_add_list to static inline
    if CONFIG_NET_RX_BUSY_POLL is not defined
  - define some functions as static

Signed-off-by: Stefan Roesch <shr@...kernel.io>

Stefan Roesch (3):
  io_uring: add napi busy polling support
  io_uring: add api to set / get napi configuration.
  io_uring: add api to set napi prefer busy poll

 include/linux/io_uring_types.h |   8 +
 include/uapi/linux/io_uring.h  |  12 ++
 io_uring/io_uring.c            | 302 +++++++++++++++++++++++++++++++++
 io_uring/napi.h                |  22 +++
 io_uring/poll.c                |   3 +
 io_uring/sqpoll.c              |  10 ++
 6 files changed, 357 insertions(+)
 create mode 100644 io_uring/napi.h

base-commit: ab290eaddc4c41b237b9a366fa6a5527be890b84
-- 
2.30.2