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 0F112C433E0 for ; Tue, 26 May 2020 17:35:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DBB8A20823 for ; Tue, 26 May 2020 17:35:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h5ceQ3ER" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389304AbgEZRfy (ORCPT ); Tue, 26 May 2020 13:35:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389270AbgEZRfs (ORCPT ); Tue, 26 May 2020 13:35:48 -0400 Received: from mail-ej1-x641.google.com (mail-ej1-x641.google.com [IPv6:2a00:1450:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34566C03E96D; Tue, 26 May 2020 10:35:48 -0700 (PDT) Received: by mail-ej1-x641.google.com with SMTP id se13so24689749ejb.9; Tue, 26 May 2020 10:35:48 -0700 (PDT) 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=1dNRVhEWH4GCqg+T6vhCKgSZ3Uxjhegqgc6JAK8cXG0=; b=h5ceQ3ERpEUrsHMLuRCi0TaKbPggwwlKIxiNUQ84CddADuYhUWrp/8R5aUfYgS7OQa DT0HfNAVbZz7guroDGiDZiYgODSJPjXDAaKGf+6KmuJVHfwHYdbQJyR5TdA4wcsplBBl AvAuYzUKez7GR8eusxkvXOQX/GnZpWG741B5jTc68RzsNN/OZStnmWNvt35hf2tKidvh Tc58lX2u7P+ic8roDwKXZbfAOnvoVoWeR2GL+coU4srBMVwPN4pijlfG91hp0LLKLcNH JeuOdusN+V9gGGvHNOI/4judxgy9QORqFNjtK4qPza9bClCzUBdlzOscXkEhIlnIMEtr 9Xug== 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=1dNRVhEWH4GCqg+T6vhCKgSZ3Uxjhegqgc6JAK8cXG0=; b=Tp0HegR424SD7PrhJcDbkpYTvs+CJLziZ4heoF+H8DFah9JhncsiiLQqWmVQQpme6s Gurv2N4IzCnXJTArM/2Co2pHTq+cK0p8IDHg5o18743rkS2erBa4w/yhEXrp0mMSi1w+ uueQNo1bwFiSgmpLB0uNmvQ6XXnzyoakNIEYNBRsFq4BEwnPfZ9ZcCpXlpbcB3E/vm9a ajcKIYBe1MoihpZsqoit2x9vkSe4wQbJUm0yvNdp7iHTPytCl+6zZvBir5xa6/yHekRB XRUtV0sWtyBShnwO+AD7k7qYrUG72aNyMvd7KeBSL5l4t7YoR2uPyC/JEAij7ueXEuPD d+Iw== X-Gm-Message-State: AOAM531U7iSfy6wBuMMmnKsJsKpHIBCgUyCLyMn/6YF40mZSAxqD6Hg6 icQqOWwG6oJD9T/UiEONm2w= X-Google-Smtp-Source: ABdhPJzpajZIrf89uoVrNG8j5X268+SwDB2Tndpkr/lHIC3uqsEi0hAWabPkyX/bmQHZTDU71f6miA== X-Received: by 2002:a17:906:68d2:: with SMTP id y18mr2168088ejr.248.1590514546828; Tue, 26 May 2020 10:35:46 -0700 (PDT) Received: from localhost.localdomain ([5.100.193.151]) by smtp.gmail.com with ESMTPSA id bz8sm391326ejc.94.2020.05.26.10.35.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 10:35:46 -0700 (PDT) From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/6] io_uring: separate DRAIN flushing into a cold path Date: Tue, 26 May 2020 20:34:05 +0300 Message-Id: <2f9403ad657d7f8eaaa2687d68a2d05599812e7e.1590513806.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 io_commit_cqring() assembly doesn't look good with extra code handling drained requests. IOSQE_IO_DRAIN is slow and discouraged to be used in a hot path, so try to minimise its impact by putting it into a helper and doing a fast check. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 067ebdeb1ba4..acf6ce9eee68 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -982,19 +982,6 @@ static inline bool req_need_defer(struct io_kiocb *req) return false; } -static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) -{ - struct io_kiocb *req; - - req = list_first_entry_or_null(&ctx->defer_list, struct io_kiocb, list); - if (req && !req_need_defer(req)) { - list_del_init(&req->list); - return req; - } - - return NULL; -} - static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx) { struct io_kiocb *req; @@ -1127,6 +1114,19 @@ static void io_kill_timeouts(struct io_ring_ctx *ctx) spin_unlock_irq(&ctx->completion_lock); } +static void __io_queue_deferred(struct io_ring_ctx *ctx) +{ + do { + struct io_kiocb *req = list_first_entry(&ctx->defer_list, + struct io_kiocb, list); + + if (req_need_defer(req)) + break; + list_del_init(&req->list); + io_queue_async_work(req); + } while (!list_empty(&ctx->defer_list)); +} + static void io_commit_cqring(struct io_ring_ctx *ctx) { struct io_kiocb *req; @@ -1136,8 +1136,8 @@ static void io_commit_cqring(struct io_ring_ctx *ctx) __io_commit_cqring(ctx); - while ((req = io_get_deferred_req(ctx)) != NULL) - io_queue_async_work(req); + if (unlikely(!list_empty(&ctx->defer_list))) + __io_queue_deferred(ctx); } static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) -- 2.24.0