From patchwork Fri Feb 3 06:08:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13127036 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 32455C64EC3 for ; Fri, 3 Feb 2023 06:09:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231770AbjBCGJI (ORCPT ); Fri, 3 Feb 2023 01:09:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231593AbjBCGJG (ORCPT ); Fri, 3 Feb 2023 01:09:06 -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 D51D3728DE for ; Thu, 2 Feb 2023 22:09:04 -0800 (PST) Received: by dev0134.prn3.facebook.com (Postfix, from userid 425415) id 964F96296799; Thu, 2 Feb 2023 22:08:52 -0800 (PST) From: Stefan Roesch To: kernel-team@fb.com Cc: shr@devkernel.io, axboe@kernel.dk, olivier@trillion01.com, netdev@vger.kernel.org, io-uring@vger.kernel.org, kuba@kernel.org, ammarfaizi2@gnuweeb.org Subject: [PATCH v7 0/3] io_uring: add napi busy polling support Date: Thu, 2 Feb 2023 22:08:47 -0800 Message-Id: <20230203060850.3060238-1-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: - 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 (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 | 10 ++ include/uapi/linux/io_uring.h | 12 ++ io_uring/io_uring.c | 297 +++++++++++++++++++++++++++++++++ io_uring/napi.h | 23 +++ io_uring/poll.c | 2 + io_uring/sqpoll.c | 17 ++ 6 files changed, 361 insertions(+) create mode 100644 io_uring/napi.h base-commit: c0b67534c95c537f7a506a06b98e5e85d72e2b7d