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=ham 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 0B0A1C2D0C0 for ; Sat, 21 Dec 2019 16:15:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D6E50206EF for ; Sat, 21 Dec 2019 16:15:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JkPvRb+B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727162AbfLUQP5 (ORCPT ); Sat, 21 Dec 2019 11:15:57 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:43383 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726107AbfLUQP4 (ORCPT ); Sat, 21 Dec 2019 11:15:56 -0500 Received: by mail-wr1-f65.google.com with SMTP id d16so12276881wre.10; Sat, 21 Dec 2019 08:15:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=h+czerSo1XAoQq8sqnK90pcICbUxRS+KoG3fOEYG01k=; b=JkPvRb+BO93GQZzZ09XvihTuia6YXz/PwpwohyAH/1UTKFrA4mewEOMwtZSK8mY7wX +YHg6o0BmLtT7gh1XllVXV7WiUAmOT0CAEVdaPcxY2y2JIbC/ylEq1WRTcnCdyMJ0oDP CXogOpUDyz2TJgj3P0Uj4k4hQ3zzZJRMQoePQkiabJa8sBBZE5XnbRyuqU34W8SmClBM m0t+allKK46MbW6dQSGQXepv659LyBGH4CttXSoFhGVXPlhJUUSJMASwweCtKpDG5JgZ aAJAqiqVQ30CU6TiXBlzk2K4G6e48L89WgBD15D/xwBX2KL2P/tqQYYqutAAOCeRxIwl zXfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=h+czerSo1XAoQq8sqnK90pcICbUxRS+KoG3fOEYG01k=; b=Uo89EDXh8Vw6oWHT/9VmYZsEIEWzgqMiLLOuA9rIXqfHqzAKySkZfrIyJFOPawhp0b 3748h7+XPSn2iQT8l4Ro3VPCxNfQsajihHpOrpmov0QYsw8kPi5NzvWVcjVyZlJutmG+ nuCb7nolZSzi7+40eKcGrz5hlYbquY7lOq1tD34FrIneSWIY6rIZFYPS6v56qpexyJOv qjVa8l7+OQ9OsYWso1t2VmlcX299r7/s2tsKngDMMfU/U2RSs3tvPAk0QYhVRGeYfHGx otXVaC8XUaEb/U5g2Q3v042Y6S4PQnLMGbw7tY9nt9WpRsWCmHkP5G4ETWI6r3fmh0Ei Sp4Q== X-Gm-Message-State: APjAAAWIRYz6qdtTjYKuD1MnCIItJb7XI6zpXGYTz7vOwhwkscS+CsKw LnrDBl9M7o2b1JLf5ri+k8k= X-Google-Smtp-Source: APXvYqxEs07NBMTqb2ZFc+aRcun6y0ZpI7gQlsmdwsOnRU4EC6tfnrcjuwVeydo1Mf9eHsa8nDjxgw== X-Received: by 2002:a5d:5345:: with SMTP id t5mr22332197wrv.0.1576944954290; Sat, 21 Dec 2019 08:15:54 -0800 (PST) Received: from localhost.localdomain ([109.126.149.134]) by smtp.gmail.com with ESMTPSA id o129sm13831260wmb.1.2019.12.21.08.15.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 21 Dec 2019 08:15:53 -0800 (PST) From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tejun Heo , Dennis Zhou , Christoph Lameter Subject: [PATCH v2 2/3] io_uring: batch getting pcpu references Date: Sat, 21 Dec 2019 19:15:08 +0300 Message-Id: <229f00564ac243cee0bfef8372a8581efedc0da2.1576944502.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(). basic benchmark with submit and wait 128 non-linked nops showed ~5% performance gain. (7044 KIOPS vs 7423) Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 513f1922ce6a..5392134f042f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1045,9 +1045,6 @@ 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)) @@ -4391,6 +4388,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, struct io_submit_state state, *statep = NULL; struct io_kiocb *link = NULL; int i, submitted = 0; + unsigned int extra_refs; bool mm_fault = false; /* if we have a backlog and couldn't flush it all, return BUSY */ @@ -4400,6 +4398,10 @@ 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; + extra_refs = nr; + if (nr > IO_PLUG_THRESHOLD) { io_submit_state_start(&state, nr); statep = &state; @@ -4415,6 +4417,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, submitted = -EAGAIN; break; } + --extra_refs; if (!io_get_sqring(ctx, req, &sqe)) { __io_free_req(req); break; @@ -4451,6 +4454,8 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, io_queue_link_head(link); if (statep) io_submit_state_end(&state); + if (extra_refs) + percpu_ref_put_many(&ctx->refs, extra_refs); /* Commit SQ ring head once we've consumed and submitted all SQEs */ io_commit_sqring(ctx); -- 2.24.0