From patchwork Thu Nov 24 09:35:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Yudaken X-Patchwork-Id: 13054746 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 5C76AC4332F for ; Thu, 24 Nov 2022 09:36:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229753AbiKXJgm (ORCPT ); Thu, 24 Nov 2022 04:36:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229773AbiKXJgl (ORCPT ); Thu, 24 Nov 2022 04:36:41 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6EC112294A for ; Thu, 24 Nov 2022 01:36:39 -0800 (PST) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2AO7r6NK026397 for ; Thu, 24 Nov 2022 01:36:39 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=meta.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-type : content-transfer-encoding : mime-version; s=s2048-2021-q4; bh=lGhq9H6BOQHa/c7KCccQkOPCfll7ETMh/0j2/9zqCf4=; b=AwOxUNVFCz+bP/FRh/NEL8vdW70s2q4prq6EwuCGSUegWtIAtmNhTfuRDh2QP1FJG9TM w0XbB7uUN1anEtqqKvegLpTLEX2TeUJoLwizZd+pDoMEUTKdGL0DOf21ZPztlT8aJ6tI TvEUZkxhWWzRzQW37nzZOZS1AIeaWru0WWCfB27ZtfNRcd/Wr26FfzxWQfDmk+mfJeq4 KLngB8RhIeOBhIXIvzCK4fvyvDcjNCm3+cItS0CFpg93bkGYdoMSZ59P0bF1iZUOucK0 NGyvZw+96Evmbo9g22iwaMYo5UDUY5vNv4JeFSVhFy4Dhwuftg/tU/3FHbrhL7rRGi1Z oA== Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3m1cg3s8x9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 24 Nov 2022 01:36:39 -0800 Received: from twshared7043.05.ash9.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 24 Nov 2022 01:36:38 -0800 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id C360BA173A14; Thu, 24 Nov 2022 01:36:20 -0800 (PST) From: Dylan Yudaken To: Jens Axboe , Pavel Begunkov CC: , , Dylan Yudaken Subject: [PATCH for-next v3 4/9] io_uring: allow defer completion for aux posted cqes Date: Thu, 24 Nov 2022 01:35:54 -0800 Message-ID: <20221124093559.3780686-5-dylany@meta.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221124093559.3780686-1-dylany@meta.com> References: <20221124093559.3780686-1-dylany@meta.com> X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: -YVLCDuxVHbCkYTYeHhBj8PMqWd-TCsX X-Proofpoint-GUID: -YVLCDuxVHbCkYTYeHhBj8PMqWd-TCsX X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-11-24_07,2022-11-23_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Multishot ops cannot use the compl_reqs list as the request must stay in the poll list, but that means they need to run each completion without benefiting from batching. Here introduce batching infrastructure for only small (ie 16 byte) CQEs. This restriction is ok because there are no use cases posting 32 byte CQEs. In the ring keep a batch of up to 16 posted results, and flush in the same way as compl_reqs. 16 was chosen through experimentation on a microbenchmark ([1]), as well as trying not to increase the size of the ring too much. This increases the size to 1472 bytes from 1216. [1]: https://github.com/DylanZA/liburing/commit/9ac66b36bcf4477bfafeff1c5f107896b7ae31cf Run with $ make -j && ./benchmark/reg.b -s 1 -t 2000 -r 10 Gives results: baseline 8309 k/s 8 18807 k/s 16 19338 k/s 32 20134 k/s Suggested-by: Pavel Begunkov Signed-off-by: Dylan Yudaken --- include/linux/io_uring_types.h | 2 ++ io_uring/io_uring.c | 27 ++++++++++++++++++++++++--- 2 files changed, 26 insertions(+), 3 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index f5b687a787a3..accdfecee953 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -174,7 +174,9 @@ struct io_submit_state { bool plug_started; bool need_plug; unsigned short submit_nr; + unsigned int cqes_count; struct blk_plug plug; + struct io_uring_cqe cqes[16]; }; struct io_ev_fd { diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index cbd271b6188a..53b61b5cde80 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -167,7 +167,8 @@ EXPORT_SYMBOL(io_uring_get_socket); static inline void io_submit_flush_completions(struct io_ring_ctx *ctx) { - if (!wq_list_empty(&ctx->submit_state.compl_reqs)) + if (!wq_list_empty(&ctx->submit_state.compl_reqs) || + ctx->submit_state.cqes_count) __io_submit_flush_completions(ctx); } @@ -802,6 +803,21 @@ bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags return false; } +static void __io_flush_post_cqes(struct io_ring_ctx *ctx) + __must_hold(&ctx->uring_lock) +{ + struct io_submit_state *state = &ctx->submit_state; + unsigned int i; + + lockdep_assert_held(&ctx->uring_lock); + for (i = 0; i < state->cqes_count; i++) { + struct io_uring_cqe *cqe = &state->cqes[i]; + + io_fill_cqe_aux(ctx, cqe->user_data, cqe->res, cqe->flags, true); + } + state->cqes_count = 0; +} + bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags, bool allow_overflow) @@ -1325,6 +1341,9 @@ static void __io_submit_flush_completions(struct io_ring_ctx *ctx) struct io_submit_state *state = &ctx->submit_state; io_cq_lock(ctx); + /* must come first to preserve CQE ordering in failure cases */ + if (state->cqes_count) + __io_flush_post_cqes(ctx); wq_list_for_each(node, prev, &state->compl_reqs) { struct io_kiocb *req = container_of(node, struct io_kiocb, comp_list); @@ -1334,8 +1353,10 @@ static void __io_submit_flush_completions(struct io_ring_ctx *ctx) } io_cq_unlock_post(ctx); - io_free_batch_list(ctx, state->compl_reqs.first); - INIT_WQ_LIST(&state->compl_reqs); + if (!wq_list_empty(&ctx->submit_state.compl_reqs)) { + io_free_batch_list(ctx, state->compl_reqs.first); + INIT_WQ_LIST(&state->compl_reqs); + } } /*