From patchwork Thu Jan 5 10:44:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13089689 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 B3579C53210 for ; Thu, 5 Jan 2023 10:46:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232803AbjAEKpu (ORCPT ); Thu, 5 Jan 2023 05:45:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232769AbjAEKpi (ORCPT ); Thu, 5 Jan 2023 05:45:38 -0500 Received: from mail-wr1-x431.google.com (mail-wr1-x431.google.com [IPv6:2a00:1450:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A3DF3E0E9 for ; Thu, 5 Jan 2023 02:45:37 -0800 (PST) Received: by mail-wr1-x431.google.com with SMTP id co23so35717094wrb.4 for ; Thu, 05 Jan 2023 02:45:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=F+dBSIOzXtuC/wWGbmLiyueE1g9asRHSjL8PxeYuA+Y=; b=gHsjo+i1IeZbogwb4TkdpvkM87U4/vBTAKrKjY6CG9ArfgSt5YTD2hyYgXfIZ/Qog/ tWnckjpqxkckCJNbD1WAh0Y0F5KJq651/wLI3fFp6HKoGxZLWyM15+bvdpqci1uRQu1Y OZAO8YxLsNepLj+kaRfUSxCjdV4Kc5tilg1vT56bwbpGdy6F8gyEAtYjkQuRSXi/uKnJ zi+79woIy7adxRCRleSdXVzwZewg6xX5QuyFS0rMZ+7Y8XhX98mlzm/WmOc+hdZidZLT J1pueykcBH/+lAclr3LojcxHHnuyFzFOXkGPdiIgfEcvctiBpG0652hCkhUagL017uWa dEvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=F+dBSIOzXtuC/wWGbmLiyueE1g9asRHSjL8PxeYuA+Y=; b=L9uwrHBi+jlJOEpO1sD1sLF0Pe0YWMUpJInIbUa3O4Hv4QbTOc2Hg6wqAJMhPZGP9Z xiRTfzbvuyZMZabdkwdM2InoYdH939qeVUVWvUbX01prAg8Q2SkAhiKRmZKe/2sQocoN w/MJsh4KVeB8bj4wGJZD5Glt2nvbRrqMP9/GfnmLUPvith9yCbnlsSiiXHR+mKdBXyU1 KmBw/CxNfIN/SC+hXHdET43ieZx5my9NV5MSxZ4oKV514NyjOv69H4ov35p4Sj6Lx/lz 9Tspjl1cPLT3rSAXmbyIw/FsYUhThKoCgtJ89wjMC0BC4URPgUc3OWGzfi2/mfcEQw+q vizg== X-Gm-Message-State: AFqh2koEbxDzDkHn6CXEJkUlS25Z7sHaCupcBVAWwJL/na177WGfLDRo zoi+OfED32bFOYBv7+u4GvBpzEBb0oY= X-Google-Smtp-Source: AMrXdXu1aCPZJ4Yz2DVjd+2jTeW0kcg5MQ1UAiJH3b8ub5mg9PjS70KYUSGV2eedmBxfzJ4WnAuDSA== X-Received: by 2002:adf:f4c5:0:b0:291:3f93:b7d1 with SMTP id h5-20020adff4c5000000b002913f93b7d1mr13114114wrp.64.1672915535896; Thu, 05 Jan 2023 02:45:35 -0800 (PST) Received: from 127.com ([2620:10d:c092:600::2:1e6c]) by smtp.gmail.com with ESMTPSA id e16-20020adfdbd0000000b002362f6fcaf5sm36129664wrj.48.2023.01.05.02.45.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Jan 2023 02:45:35 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH] io_uring: fix CQ waiting timeout handling Date: Thu, 5 Jan 2023 10:44:33 +0000 Message-Id: <609a38a65f91643f9f9706b983a8aaa0e3001d77.1672915374.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Jiffy to ktime CQ waiting conversion broke how we treat timeouts, in particular we rearm it anew every time we get into io_cqring_wait_schedule() without adjusting the timeout. Waiting for 2 CQEs and getting a task_work in the middle may double the timeout value, or even worse in some cases task may wait indefinitely. Cc: stable@vger.kernel.org Fixes: 228339662b398 ("io_uring: don't convert to jiffies for waiting on timeouts") Signed-off-by: Pavel Begunkov --- io_uring/io_uring.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index adecdf65b130..71cd2edcc432 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2401,7 +2401,7 @@ int io_run_task_work_sig(struct io_ring_ctx *ctx) /* when returns >0, the caller should retry */ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, struct io_wait_queue *iowq, - ktime_t timeout) + ktime_t *timeout) { int ret; unsigned long check_cq; @@ -2419,7 +2419,7 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) return -EBADR; } - if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS)) + if (!schedule_hrtimeout(timeout, HRTIMER_MODE_ABS)) return -ETIME; return 1; } @@ -2489,7 +2489,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, } prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq, TASK_INTERRUPTIBLE); - ret = io_cqring_wait_schedule(ctx, &iowq, timeout); + ret = io_cqring_wait_schedule(ctx, &iowq, &timeout); cond_resched(); } while (ret > 0);