From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 98AB23074A4 for ; Tue, 14 Oct 2025 04:19:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760415591; cv=none; b=tMuXCkyMepsbbHzcV1c+uci5c/vNB6ui8sIm/UZxc7l7K2I42JNBUQLE0+YXQfmIeb2+qesD7W416PIJrThG73f3Pe5YkRjS/M91opTem9VOpAw+vt+tAKiMUOPUiusYaXEnBA2vnpj7ya1BIPkrlu8O9J+sZzIIfMNxBza3SvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760415591; c=relaxed/simple; bh=efRncSBox4EGtM3nSmQtO2KgUENSolfoFMtV3iP5wsg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=t0SNZ9UthVCIYNKcXOVdrA5gaMi2c/i213lCJlPF02hzPqBuHOVIGHqeXZ0ZAzMtRmNzWVJzUTJQB/0zGL1IveTttIz2mUC5KGDDHoH4lY9AoAzF99Wzg5kvATAzQDpaGM/z+RndHRhlRFpJ0Cx40QbamRz/PYu0yzI81Pk7GOs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Tvwrugtq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Tvwrugtq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56663C4CEE7; Tue, 14 Oct 2025 04:19:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760415591; bh=efRncSBox4EGtM3nSmQtO2KgUENSolfoFMtV3iP5wsg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=TvwrugtqZ23dFB/les8IOa7mhmzv/nj3tlgQQrlZCXnB3w49BZ2AL3pCKxQ5OV3tn 2NkaK0c4h5lT9/L6Ug6cxKhBvKmGCFswTn3cy90uuJ6GrB6QSNtOHtFkNXPgw6Z0gF LlnxwmIF+ERrzreOWXOC7/cfwHzI2PqjplN4Oed3/K9P26kpJp+HAiOt/WOJweS3dk UPy4NyC+9yKmv0m5QQSSlf5muRfTucRqK3p4nWefo/fTOnOkNEZgh7/GFD3YjuNR8f dEbDt5ZXqjF86goXzuSXC+ZrQPty0Kqf4J6VfTnVk4kz2RqGejKCnkYG13ttJ2Ryq8 riHJsMocM5ZwA== Message-ID: <19be10e7-3140-4571-bf0e-e8eec1188fec@kernel.org> Date: Tue, 14 Oct 2025 13:19:47 +0900 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] block/mq-deadline: Switch back to a single dispatch list To: Bart Van Assche , Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Yu Kuai , chengkaitao References: <20251013192803.4168772-1-bvanassche@acm.org> <20251013192803.4168772-3-bvanassche@acm.org> From: Damien Le Moal Content-Language: en-US Organization: Western Digital Research In-Reply-To: <20251013192803.4168772-3-bvanassche@acm.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2025/10/14 4:28, Bart Van Assche wrote: > Commit c807ab520fc3 ("block/mq-deadline: Add I/O priority support") > modified the behavior of request flag BLK_MQ_INSERT_AT_HEAD from > dispatching a request before other requests into dispatching a request > before other requests with the same I/O priority. This is not correct since > BLK_MQ_INSERT_AT_HEAD is used when requeuing requests and also when a flush > request is inserted. Both types of requests should be dispatched as soon > as possible. Hence, make the mq-deadline I/O scheduler again ignore the I/O > priority for BLK_MQ_INSERT_AT_HEAD requests. > > Cc: Damien Le Moal > Cc: Yu Kuai > Reported-by: chengkaitao > Closes: https://lore.kernel.org/linux-block/20251009155253.14611-1-pilgrimtao@gmail.com/ > Fixes: c807ab520fc3 ("block/mq-deadline: Add I/O priority support") > Signed-off-by: Bart Van Assche Nice cleanup ! Reviewed-by: Damien Le Moalv -- Damien Le Moal Western Digital Research