From patchwork Thu Jan 5 10:49:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13089690 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 84DD4C3DA7A for ; Thu, 5 Jan 2023 10:51:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232196AbjAEKu7 (ORCPT ); Thu, 5 Jan 2023 05:50:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232214AbjAEKu2 (ORCPT ); Thu, 5 Jan 2023 05:50:28 -0500 Received: from mail-wm1-x335.google.com (mail-wm1-x335.google.com [IPv6:2a00:1450:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1418559F4 for ; Thu, 5 Jan 2023 02:50:13 -0800 (PST) Received: by mail-wm1-x335.google.com with SMTP id g10so13918996wmo.1 for ; Thu, 05 Jan 2023 02:50:13 -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=w77psyvSvnkLAXlGYEMZalmNp9OObVymnj+u/wsnPl8=; b=S/eVQryr10ApSIWT7Xy/49ple8aFvdfov/+TsVWRiv6VP1eu5EYANYp4Co/n3OV01T 9Ksq9DeO6sFNfQ2DnJ/BJd1v4EPfNDVEU+QIaMMsZotIkWAOnF3c694ZSQU0/9MuUhez xCB7nO6TpraMWpwFxgXRYzmU6teIH1J8arFs84jogKze1BX9nwcnDUeS3kbLy8RQqUSC sT7QTuorclfHxPUoBKIfhub4zgpGpnUNnqFjEVpAUiW1d1Ipb2Dh6ki3ucFgqP2LDivV 5hNUYn+jrYqffANS2Xjb+XgTcALhpekVRxHCFt8N7rvS4BJ5kOVrVCMHs/36F45mK4Tl qODg== 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=w77psyvSvnkLAXlGYEMZalmNp9OObVymnj+u/wsnPl8=; b=TwOYUhv74dabLOqTUPV3cS7cjCceqIc0pRzWC6sHIPusgGeklOcm3yvSoPY1qENNta H8QhD4jBZwvdmxwmZp27Xgo+TBn0Jt1GKjBcb1KX1AucynkmV6OhsdGuJoRqYElvuoJl VB3WuueTyXS2Q9qC0G4+ADbxMP1Cs69z6co2ZYvpENdh5hCaiTs/zhhivEqMF4GfVvh2 rlrcYcIaNDexC+9t0ImF93P050QBf0Juy8IAMWkbPMsqOOSCj0cDoR+wdC4F8j/6jS/j 3eiua4hNoVSjckSu/5Gc32+RhO5dDMaIiOSv2FfNfLZRrKWAbhOOAvLIg1D9UWTS2FHd JDxg== X-Gm-Message-State: AFqh2kqf36qSbGeyzwpwbOY8L5RN41WcxYEyemroezDIDn/TK8swOXjZ ax4Gr+S8bO3oqEGFRXSsxd2LySawyFg= X-Google-Smtp-Source: AMrXdXvtOGRxcBF0Sv91XxwPc+QsyErDpsvYi9Ty99tEvFgoa0mMNo2OZXq8+EnGPcHyhApO1K1spw== X-Received: by 2002:a05:600c:601b:b0:3d3:56ce:5693 with SMTP id az27-20020a05600c601b00b003d356ce5693mr35328852wmb.17.1672915812221; Thu, 05 Jan 2023 02:50:12 -0800 (PST) Received: from 127.com ([2620:10d:c092:600::2:5c5f]) by smtp.gmail.com with ESMTPSA id v16-20020a05600c445000b003c6c3fb3cf6sm2185035wmn.18.2023.01.05.02.50.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Jan 2023 02:50:11 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH v2] io_uring: fix CQ waiting timeout handling Date: Thu, 5 Jan 2023 10:49:15 +0000 Message-Id: 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 --- v2: rebase 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 472574192dd6..2ac1cd8d23ea 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2470,7 +2470,7 @@ 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; @@ -2488,7 +2488,7 @@ 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; /* @@ -2564,7 +2564,7 @@ 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); if (__io_cqring_events_user(ctx) >= min_events) break; cond_resched();