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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37D80C6FD1D for ; Wed, 15 Mar 2023 12:27:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232455AbjCOM07 (ORCPT ); Wed, 15 Mar 2023 08:26:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232445AbjCOM0p (ORCPT ); Wed, 15 Mar 2023 08:26:45 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41C1B5983E for ; Wed, 15 Mar 2023 05:25:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 92C5DB81E04 for ; Wed, 15 Mar 2023 12:25:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5BE1C433EF; Wed, 15 Mar 2023 12:25:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678883148; bh=5xBQB/Lp4TNL6xNwavqKDOHU6MK+ON48BlW4BdDgzEM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OSfFvFeUHCVDO/T05AoKMl/8HzogJjVof36TW8imU8/3Q0hhImbZY6Q6q1vQ9wPvA v0LwfNM6Y9AGXSnOyjF17cLHQL4/GcDFoQKzgzQKbGNYNmSIqPeKxai/3Txspa6UeX jyIXYwIwX4oyZtYXeoiRiLcl+CtMC5G8HBjlI3V4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe , Sasha Levin Subject: [PATCH 5.15 033/145] brd: mark as nowait compatible Date: Wed, 15 Mar 2023 13:11:39 +0100 Message-Id: <20230315115740.150187791@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230315115738.951067403@linuxfoundation.org> References: <20230315115738.951067403@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jens Axboe [ Upstream commit 67205f80be9910207481406c47f7d85e703fb2e9 ] By default, non-mq drivers do not support nowait. This causes io_uring to use a slower path as the driver cannot be trust not to block. brd can safely set the nowait flag, as worst case all it does is a NOIO allocation. For io_uring, this makes a substantial difference. Before: submitter=0, tid=453, file=/dev/ram0, node=-1 polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128 Engine=io_uring, sq_ring=128, cq_ring=128 IOPS=440.03K, BW=1718MiB/s, IOS/call=32/31 IOPS=428.96K, BW=1675MiB/s, IOS/call=32/32 IOPS=442.59K, BW=1728MiB/s, IOS/call=32/31 IOPS=419.65K, BW=1639MiB/s, IOS/call=32/32 IOPS=426.82K, BW=1667MiB/s, IOS/call=32/31 and after: submitter=0, tid=354, file=/dev/ram0, node=-1 polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128 Engine=io_uring, sq_ring=128, cq_ring=128 IOPS=3.37M, BW=13.15GiB/s, IOS/call=32/31 IOPS=3.45M, BW=13.46GiB/s, IOS/call=32/31 IOPS=3.43M, BW=13.42GiB/s, IOS/call=32/32 IOPS=3.43M, BW=13.39GiB/s, IOS/call=32/31 IOPS=3.43M, BW=13.38GiB/s, IOS/call=32/31 or about an 8x in difference. Now that brd is prepared to deal with REQ_NOWAIT reads/writes, mark it as supporting that. Cc: stable@vger.kernel.org # 5.10+ Link: https://lore.kernel.org/linux-block/20230203103005.31290-1-p.raghav@samsung.com/ Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/brd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 63ac5cd523408..76ce6f766d55e 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -421,6 +421,7 @@ static int brd_alloc(int i) /* Tell the block layer that this is not a rotational device */ blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); + blk_queue_flag_set(QUEUE_FLAG_NOWAIT, disk->queue); err = add_disk(disk); if (err) goto out_cleanup_disk; -- 2.39.2