From patchwork Thu Feb 9 23:01:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13135135 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 297E0C64EC5 for ; Thu, 9 Feb 2023 23:02:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230385AbjBIXC1 (ORCPT ); Thu, 9 Feb 2023 18:02:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230408AbjBIXCY (ORCPT ); Thu, 9 Feb 2023 18:02:24 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73E305EBE3 for ; Thu, 9 Feb 2023 15:02:16 -0800 (PST) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id A6EB06AB676D; Thu, 9 Feb 2023 15:02:01 -0800 (PST) From: Stefan Roesch To: io-uring@vger.kernel.org, kernel-team@fb.com Cc: shr@devkernel.io, axboe@kernel.dk, ammarfaizi2@gnuweeb.org Subject: [PATCH v8 0/7] io_uring: add napi busy polling support Date: Thu, 9 Feb 2023 15:01:37 -0800 Message-Id: <20230209230144.465620-1-shr@devkernel.io> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 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. For faster access it also adds a hash table. When a new napi id is added, the hash table is used to locate if the napi id has already been added. When processing the busy poll loop the list is used to process the individual elements. 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: - V8: - added new file napi.c and add napi functions to this file - added NAPI_LIST_HEAD function so no ifdef is necessary - added io_napi_init and io_napi_free function - added io_napi_setup_busy loop helper function - added io_napi_adjust_busy_loop helper function - added io_napi_end_busy_loop helper function - added io_napi_sqpoll_busy_poll helper function - some of the definitions in napi.h are macros to avoid ifdef definitions in io_uring.c, poll.c and sqpoll.c - changed signature of io_napi_add function - changed size of hashtable to 16. The number of entries is limited by the number of nic queues. - Removed ternary in io_napi_blocking_busy_loop - Rewrote io_napi_blocking_busy_loop to make it more readable - Split off 3 more patches - V7: - allow unregister with NULL value for arg parameter - return -EOPNOTSUPP if CONFIG_NET_RX_BUSY_POLL is not enabled - V6: - Add a hash table on top of the list for faster access during the add operation. The linked list and the hash table use the same data structure - V5: - Refreshed to 6.1-rc6 - Use copy_from_user instead of memdup/kfree - Removed the moving of napi_busy_poll_to - Return -EINVAL if any of the reserved or padded fields are not 0. - 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 Stefan Roesch (7): io-uring: move io_wait_queue definition to header file io-uring: add napi fields to io_ring_ctx io-uring: add busy poll timeout, prefer busy poll to io_wait_queue io-uring: add napi busy poll support io-uring: add sqpoll support for napi busy poll io_uring: add api to set / get napi configuration. io_uring: add api to set / get napi configuration. include/linux/io_uring_types.h | 10 + include/uapi/linux/io_uring.h | 12 ++ io_uring/Makefile | 1 + io_uring/io_uring.c | 42 ++-- io_uring/io_uring.h | 26 +++ io_uring/napi.c | 345 +++++++++++++++++++++++++++++++++ io_uring/napi.h | 64 ++++++ io_uring/poll.c | 2 + io_uring/sqpoll.c | 4 + 9 files changed, 485 insertions(+), 21 deletions(-) create mode 100644 io_uring/napi.c create mode 100644 io_uring/napi.h base-commit: 2f2bb1ffc9983e227424d0787289da5483b0c74f