From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06841C2D0CE for ; Sat, 28 Dec 2019 11:13:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D110F20748 for ; Sat, 28 Dec 2019 11:13:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vh/EItAj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726674AbfL1LNq (ORCPT ); Sat, 28 Dec 2019 06:13:46 -0500 Received: from mail-wr1-f67.google.com ([209.85.221.67]:44685 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726584AbfL1LNn (ORCPT ); Sat, 28 Dec 2019 06:13:43 -0500 Received: by mail-wr1-f67.google.com with SMTP id q10so28349970wrm.11; Sat, 28 Dec 2019 03:13:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=YHYJcDrGIHRFm53VlzRjbvCMqJEk7QWJgVaPxjySsxc=; b=vh/EItAjQHTrj6A1QVr/MzFGHyyT1AZ/5rFAYS6FzVX0jGjJuT7XEYbILe0wmT223f JymM28x1E4Ce3elN0tD8rYghuKahsyIqZ8535CCo3MI3AWP9vwvX6BBBOR4s9VNBhchn VFpw2LEfI9nEIvdI8Pqwq9nk9L6hnLdRWfFEcsKpyDAvU34serb3ZHwWjNauJQR7oMH6 3ViPay0FJPt8yHQZbJooMr8m6//bECsCcIX8jagbicuOVqIK/Md4ww3/bRZUdV6oJJFO XjoyrjN26SgGAufOckjNX9tcqRPeqTxmEs7gIbrFOndjU8scRk/06FaWywGNMMpz1jS8 RM7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=YHYJcDrGIHRFm53VlzRjbvCMqJEk7QWJgVaPxjySsxc=; b=XejUUGlBfDsQZdh7BHKCxCPE2ZWAp2kkTlU/P/v4T7vxMZROPtraIZGMKuae9p51mi PqFxA7eSfJ362ImEpS02bYaBT7seN0pi043PyeNSlZsdP/5zhpX94BhWcg5eQ7sD/+U+ 1TVay05K6/FL+F2UR1cwXTcpg6Tiayk5+nVEI9lXQxaUeTs++XwcYoLKa/CXHYvcwcqz 9UKP8l8cbJh07XF0fzW8JjI8x4gRCfBBtkv8u+0yrJYlwxDcjLdek8B737+NOLLtVFaT YJTGHaHrxzXV4HGO9y88WHF5yNX4SRIeKT2Vam2kD2AmOen6li1QAQm4M6UWEZxxPIE+ upkA== X-Gm-Message-State: APjAAAVt9BSMEjMbEwo9Y/Va4g0gmKIU2rWLq497JQ85dMo8dbdVoBV4 WLMFE8C2TcKdQYtTIyXp1uw= X-Google-Smtp-Source: APXvYqwXnlafFfHpV4myorXxHzbctCqnnbxoeLtbqQwzU3btdl1WbZrKGRtpSufWrgl7Pu7p37rKdQ== X-Received: by 2002:a5d:5283:: with SMTP id c3mr57755497wrv.148.1577531621873; Sat, 28 Dec 2019 03:13:41 -0800 (PST) Received: from localhost.localdomain ([109.126.145.157]) by smtp.gmail.com with ESMTPSA id q11sm37432622wrp.24.2019.12.28.03.13.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 28 Dec 2019 03:13:41 -0800 (PST) From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 2/2] io_uring: batch getting pcpu references Date: Sat, 28 Dec 2019 14:13:03 +0300 Message-Id: <1250dad37e9b73d39066a8b464f6d2cab26eef8a.1577528535.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org percpu_ref_tryget() has its own overhead. Instead getting a reference for each request, grab a bunch once per io_submit_sqes(). ~5% throughput boost for a "submit and wait 128 nops" benchmark. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 7fc1158bf9a4..404946080e86 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1080,9 +1080,6 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; struct io_kiocb *req; - if (!percpu_ref_tryget(&ctx->refs)) - return NULL; - if (!state) { req = kmem_cache_alloc(req_cachep, gfp); if (unlikely(!req)) @@ -1141,6 +1138,14 @@ static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) } } +static void __io_req_free_empty(struct io_kiocb *req) +{ + if (likely(!io_is_fallback_req(req))) + kmem_cache_free(req_cachep, req); + else + clear_bit_unlock(0, (unsigned long *) req->ctx->fallback_req); +} + static void __io_free_req(struct io_kiocb *req) { struct io_ring_ctx *ctx = req->ctx; @@ -1162,11 +1167,9 @@ static void __io_free_req(struct io_kiocb *req) wake_up(&ctx->inflight_wait); spin_unlock_irqrestore(&ctx->inflight_lock, flags); } - percpu_ref_put(&ctx->refs); - if (likely(!io_is_fallback_req(req))) - kmem_cache_free(req_cachep, req); - else - clear_bit_unlock(0, (unsigned long *) ctx->fallback_req); + + percpu_ref_put(&req->ctx->refs); + __io_req_free_empty(req); } static bool io_link_cancel_timeout(struct io_kiocb *req) @@ -4551,6 +4554,9 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, return -EBUSY; } + if (!percpu_ref_tryget_many(&ctx->refs, nr)) + return -EAGAIN; + if (nr > IO_PLUG_THRESHOLD) { io_submit_state_start(&state, nr); statep = &state; @@ -4567,7 +4573,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, break; } if (!io_get_sqring(ctx, req, &sqe)) { - __io_free_req(req); + __io_req_free_empty(req); break; } @@ -4598,6 +4604,8 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, break; } + if (submitted != nr) + percpu_ref_put_many(&ctx->refs, nr - submitted); if (link) io_queue_link_head(link); if (statep) -- 2.24.0