From patchwork Mon Dec 28 12:44:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 354706 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 68CA9C43331 for ; Mon, 28 Dec 2020 15:03:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5069122AEC for ; Mon, 28 Dec 2020 15:03:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439411AbgL1PDo (ORCPT ); Mon, 28 Dec 2020 10:03:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:46870 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439849AbgL1OMU (ORCPT ); Mon, 28 Dec 2020 09:12:20 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 36ED02063A; Mon, 28 Dec 2020 14:11:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609164699; bh=14uTw111GyeL+dWcdEzV0CgjyY0Czhgw3ueJofuF2NA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KhAAIc9Es94xslov9u4n/t5zx6pG7hfpjADXtDPehlxPkrqSdEvCKMh1KeflKB3IR mJzmSd52VSSO2V0IETAfTXRctYK3XjfiFhxz8IWwFsSs0+RVIDj4Lvu09Peu4AJIWb Za/TJeNIybFBiaTSMCvM2rjXoM4XT5d1A2Dn5BGQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Sasha Levin Subject: [PATCH 5.10 266/717] SUNRPC: rpc_wake_up() should wake up tasks in the correct order Date: Mon, 28 Dec 2020 13:44:24 +0100 Message-Id: <20201228125033.755429585@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228125020.963311703@linuxfoundation.org> References: <20201228125020.963311703@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Trond Myklebust [ Upstream commit e4c72201b6ec3173dfe13fa2e2335a3ad78d4921 ] Currently, we wake up the tasks by priority queue ordering, which means that we ignore the batching that is supposed to help with QoS issues. Fixes: c049f8ea9a0d ("SUNRPC: Remove the bh-safe lock requirement on the rpc_wait_queue->lock") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- net/sunrpc/sched.c | 65 +++++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 30 deletions(-) diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index f06d7c315017c..cf702a5f7fe5d 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -675,6 +675,23 @@ struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *queue) } EXPORT_SYMBOL_GPL(rpc_wake_up_next); +/** + * rpc_wake_up_locked - wake up all rpc_tasks + * @queue: rpc_wait_queue on which the tasks are sleeping + * + */ +static void rpc_wake_up_locked(struct rpc_wait_queue *queue) +{ + struct rpc_task *task; + + for (;;) { + task = __rpc_find_next_queued(queue); + if (task == NULL) + break; + rpc_wake_up_task_queue_locked(queue, task); + } +} + /** * rpc_wake_up - wake up all rpc_tasks * @queue: rpc_wait_queue on which the tasks are sleeping @@ -683,25 +700,28 @@ EXPORT_SYMBOL_GPL(rpc_wake_up_next); */ void rpc_wake_up(struct rpc_wait_queue *queue) { - struct list_head *head; - spin_lock(&queue->lock); - head = &queue->tasks[queue->maxpriority]; + rpc_wake_up_locked(queue); + spin_unlock(&queue->lock); +} +EXPORT_SYMBOL_GPL(rpc_wake_up); + +/** + * rpc_wake_up_status_locked - wake up all rpc_tasks and set their status value. + * @queue: rpc_wait_queue on which the tasks are sleeping + * @status: status value to set + */ +static void rpc_wake_up_status_locked(struct rpc_wait_queue *queue, int status) +{ + struct rpc_task *task; + for (;;) { - while (!list_empty(head)) { - struct rpc_task *task; - task = list_first_entry(head, - struct rpc_task, - u.tk_wait.list); - rpc_wake_up_task_queue_locked(queue, task); - } - if (head == &queue->tasks[0]) + task = __rpc_find_next_queued(queue); + if (task == NULL) break; - head--; + rpc_wake_up_task_queue_set_status_locked(queue, task, status); } - spin_unlock(&queue->lock); } -EXPORT_SYMBOL_GPL(rpc_wake_up); /** * rpc_wake_up_status - wake up all rpc_tasks and set their status value. @@ -712,23 +732,8 @@ EXPORT_SYMBOL_GPL(rpc_wake_up); */ void rpc_wake_up_status(struct rpc_wait_queue *queue, int status) { - struct list_head *head; - spin_lock(&queue->lock); - head = &queue->tasks[queue->maxpriority]; - for (;;) { - while (!list_empty(head)) { - struct rpc_task *task; - task = list_first_entry(head, - struct rpc_task, - u.tk_wait.list); - task->tk_status = status; - rpc_wake_up_task_queue_locked(queue, task); - } - if (head == &queue->tasks[0]) - break; - head--; - } + rpc_wake_up_status_locked(queue, status); spin_unlock(&queue->lock); } EXPORT_SYMBOL_GPL(rpc_wake_up_status);