From patchwork Mon Feb 11 10:50:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aleksei Zakharov X-Patchwork-Id: 10805519 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EF0CC13A4 for ; Mon, 11 Feb 2019 10:51:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DF97D29FF9 for ; Mon, 11 Feb 2019 10:51:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D3E5C2A0C6; Mon, 11 Feb 2019 10:51:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7477B29FF9 for ; Mon, 11 Feb 2019 10:51:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727049AbfBKKvY (ORCPT ); Mon, 11 Feb 2019 05:51:24 -0500 Received: from forward101o.mail.yandex.net ([37.140.190.181]:34303 "EHLO forward101o.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725931AbfBKKvY (ORCPT ); Mon, 11 Feb 2019 05:51:24 -0500 Received: from mxback7j.mail.yandex.net (mxback7j.mail.yandex.net [IPv6:2a02:6b8:0:1619::110]) by forward101o.mail.yandex.net (Yandex) with ESMTP id 79ED73C01F3A; Mon, 11 Feb 2019 13:51:21 +0300 (MSK) Received: from smtp1p.mail.yandex.net (smtp1p.mail.yandex.net [2a02:6b8:0:1472:2741:0:8b6:6]) by mxback7j.mail.yandex.net (nwsmtp/Yandex) with ESMTP id 8atKKXashl-pLleWW0X; Mon, 11 Feb 2019 13:51:21 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1549882281; bh=wy4azC8/jiDFBHmmm7QO1aVpS+tnhXwoIlAL3HJBjew=; h=From:To:Cc:Subject:Date:Message-Id; b=PeXipHB6kFE8SQqidEN8GjZ6qfv8Btj3GR9XNd0gmeetfnt/JDS1wC0NciDhDWzre PHy/6KGK+wj7kf+x3aHZkCsfDlWoNYnys6pTgfNyTebeNOIa3J61AdgEa+o+cOa0Xk bqsOiWCCseVOp5MfqPoAW75jmAF1V+wYtgpqkUhQ= Authentication-Results: mxback7j.mail.yandex.net; dkim=pass header.i=@yandex.ru Received: by smtp1p.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id tz9LJo3rX9-pKnGBhMb; Mon, 11 Feb 2019 13:51:20 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (Client certificate not present) From: Aleksei Zakharov To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, Aleksei Zakharov Subject: [PATCH] block: avoid setting none scheduler if it's already none Date: Mon, 11 Feb 2019 13:50:37 +0300 Message-Id: <1549882237-28183-1-git-send-email-zakharov.a.g@yandex.ru> X-Mailer: git-send-email 2.7.4 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There's no reason to freeze queue and remove scheduler if there's no scheduler already. Signed-off-by: Aleksei Zakharov --- block/elevator.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/block/elevator.c b/block/elevator.c index f05e90d..d6d835a 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -667,8 +667,11 @@ static int __elevator_change(struct request_queue *q, const char *name) /* * Special case for mq, turn off scheduling */ - if (!strncmp(name, "none", 4)) + if (!strncmp(name, "none", 4)) { + if (!q->elevator) + return 0; return elevator_switch(q, NULL); + } strlcpy(elevator_name, name, sizeof(elevator_name)); e = elevator_get(q, strstrip(elevator_name), true);