From patchwork Thu Jun 27 12:49:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 808055 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9516017838D; Thu, 27 Jun 2024 12:49:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719492578; cv=none; b=i7joV537qiwOxAzioBltLaRXGq8slC+i/lIzyVh0rRtyM7f6O/L1WNTE4DHn5/nwvBfxOJcrvgyWji+JlKjkW8Ny1K8oUQq5WmAa0v4KJESPDoB26spuIGtFVCH1bv64+qJzdSG4ll816sjL6dQkOREpvzQ1pLQi2xaI8XdsI+U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719492578; c=relaxed/simple; bh=B/Mz61kJ0gKhqTo9TQhnVEwo9B0DXR73xnWUb5qnv70=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WCVFM8xqWi1l41G8PhcWD5hLbIx67r7xLJdJxsOMFYtWJoiNQje6BzTXo96R3ehnJH9l5yoJ/U7zUBOuYedeabSXQdLNlJMaEj9UdyrOwb6Lo/fgPdlwSsidBk46iOj6UOpb1jjMTwhmPBP599BwLxjgkJHy1n5FOTVhGQl/2is= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=bK7T0t2R; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="bK7T0t2R" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=7bza4BPcHCE+GDsbiJfWSek0v/JwxgMHleU7FQsIb/0=; b=bK7T0t2RFNyxDE7zjSaf907S5l 4rPnA0bh/NErNalALdph0xpA0FrgVOboKiKuz8eY3D0pEWtz2yhfn3IyGrI5zDTAmqwrZx+mIQx/Z WyAN7DC3EvpF6UFv3Dl0JhOlf25P1IqYSPfiDgxDd6z1E6wsMPxklTLWpjpUQ3RTbQ5syDJiAvq+U gQ6wCjfD4oHc5SyvJ3i/84SNcS8rus86koMyIpDrQx+1Knc6pamVGjEs7S0Z3cZNiLOiF7Db8tro1 GiZBDtYiWlx8/RgOzYFUnFPl4teGKFiTUUkBOeph5FnKbHjq46GXQZCPECUHnrdvkVdMLI0n1VSl7 KVcv1fCw==; Received: from [2001:4bb8:2dc:6d4c:6789:3c0c:a17:a2fe] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sMoZB-0000000AN1C-2lkE; Thu, 27 Jun 2024 12:49:34 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Ming Lei , "Md. Haris Iqbal" , Jack Wang , Kashyap Desai , Sumit Saxena , Shivasharan S , Chandrakanth patil , "Martin K. Petersen" , Sathya Prakash , Sreekanth Reddy , Suganath Prabu Subramani , linux-block@vger.kernel.org, megaraidlinux.pdl@broadcom.com, linux-scsi@vger.kernel.org, MPT-FusionLinux.pdl@broadcom.com Subject: [PATCH 1/5] loop: don't set QUEUE_FLAG_NOMERGES Date: Thu, 27 Jun 2024 14:49:11 +0200 Message-ID: <20240627124926.512662-2-hch@lst.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240627124926.512662-1-hch@lst.de> References: <20240627124926.512662-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html QUEUE_FLAG_NOMERGES isn't really a driver interface, but a user tunable. There also isn't any good reason to set it in the loop driver. The original commit adding it (5b5e20f421c0b6d "block: loop: set QUEUE_FLAG_NOMERGES for request queue of loop") claims that "It doesn't make sense to enable merge because the I/O submitted to backing file is handled page by page." which of course isn't true for multi-page bvec now, and it never has been for direct I/O, for which commit 40326d8a33d ("block/loop: allow request merge for directio mode") alredy disabled the nomerges flag. Signed-off-by: Christoph Hellwig --- drivers/block/loop.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 86b5d956dc4e02..3a116314877109 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -211,13 +211,10 @@ static void __loop_update_dio(struct loop_device *lo, bool dio) if (lo->lo_state == Lo_bound) blk_mq_freeze_queue(lo->lo_queue); lo->use_dio = use_dio; - if (use_dio) { - blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, lo->lo_queue); + if (use_dio) lo->lo_flags |= LO_FLAGS_DIRECT_IO; - } else { - blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue); + else lo->lo_flags &= ~LO_FLAGS_DIRECT_IO; - } if (lo->lo_state == Lo_bound) blk_mq_unfreeze_queue(lo->lo_queue); } @@ -2033,14 +2030,6 @@ static int loop_add(int i) } lo->lo_queue = lo->lo_disk->queue; - /* - * By default, we do buffer IO, so it doesn't make sense to enable - * merge because the I/O submitted to backing file is handled page by - * page. For directio mode, merge does help to dispatch bigger request - * to underlayer disk. We will enable merge once directio is enabled. - */ - blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue); - /* * Disable partition scanning by default. The in-kernel partition * scanning can be requested individually per-device during its