From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 E3F04171AF for ; Tue, 19 Dec 2023 12:10:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id B1AC368BFE; Tue, 19 Dec 2023 13:10:10 +0100 (CET) Date: Tue, 19 Dec 2023 13:10:10 +0100 From: Christoph Hellwig To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org, Damien Le Moal , Christoph Hellwig Subject: Re: [PATCH v2 4/4] block/mq-deadline: Prevent zoned write reordering due to I/O prioritization Message-ID: <20231219121010.GA21240@lst.de> References: <20231218211342.2179689-1-bvanassche@acm.org> <20231218211342.2179689-5-bvanassche@acm.org> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231218211342.2179689-5-bvanassche@acm.org> User-Agent: Mutt/1.5.17 (2007-11-01) On Mon, Dec 18, 2023 at 01:13:42PM -0800, Bart Van Assche wrote: > Assigning I/O priorities with the ioprio cgroup policy may cause > different I/O priorities to be assigned to write requests for the same > zone. Prevent that this causes unaligned write errors by adding zoned > writes for the same zone in the same priority queue as prior zoned > writes. I still think this is fundamentally the wrong thing to do. If you set different priorities, you want I/O to be reordered, so ignoring that is a bad thing.