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 81B82C678D4 for ; Fri, 13 Jan 2023 12:07:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240928AbjAMMG7 (ORCPT ); Fri, 13 Jan 2023 07:06:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232755AbjAMMFp (ORCPT ); Fri, 13 Jan 2023 07:05:45 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FDC5CE3C; Fri, 13 Jan 2023 03:55:59 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 105485D576; Fri, 13 Jan 2023 11:55:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1673610958; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nmntA51MWggfj/2YDUcWIh0q+nKcU1SjEV7GX306pgY=; b=geieDLdwDlsa4fYb/G1HNe6cif6PX2k4G8T0Tiw8iu4x9/JjU28S35nd+S5v+oxrwVL2EW i/CSct1atwDYw6+QAIKIbAM5Ku6trJcnI+nadLiOiEaKQnbqzshcb1XKlHmlUxxspYZl77 MX+ieX2O/0cdGHd12+p6KiBsZJGcJ0Q= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1673610958; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nmntA51MWggfj/2YDUcWIh0q+nKcU1SjEV7GX306pgY=; b=nHnPPPTTWbVclEDiL2g+NMnROxALr+7g4b74lvFRwO67qwQlksvBCeiC8F09PUbmMNuS2Z xAYNPYPOSyRdkFAw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id DB4F81358A; Fri, 13 Jan 2023 11:55:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id VnjWM81GwWMIRAAAMHmgww (envelope-from ); Fri, 13 Jan 2023 11:55:57 +0000 Message-ID: <08d6acff-9aaf-7c2f-6b4d-7fd83c7a68c6@suse.de> Date: Fri, 13 Jan 2023 12:55:57 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Content-Language: en-US To: Niklas Cassel , Paolo Valente , Jens Axboe Cc: Damien Le Moal , linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, linux-block@vger.kernel.org References: <20230112140412.667308-1-niklas.cassel@wdc.com> <20230112140412.667308-8-niklas.cassel@wdc.com> From: Hannes Reinecke Subject: Re: [PATCH v2 07/18] block: introduce duration-limits priority class In-Reply-To: <20230112140412.667308-8-niklas.cassel@wdc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 1/12/23 15:03, Niklas Cassel wrote: > From: Damien Le Moal > > Introduce the IOPRIO_CLASS_DL priority class to indicate that IOs should > be executed using duration-limits targets. The duration target to apply > to a command is indicated using the priority level. Up to 8 levels are > supported, with level 0 indiating "no limit". > > This priority class has effect only if the target device supports the > command duration limits feature and this feature is enabled by the user. > In BFQ and mq-deadline, all requests with this new priority class are > handled using the highest priority class RT and priority level 0. > > Signed-off-by: Damien Le Moal > Signed-off-by: Niklas Cassel > --- > block/bfq-iosched.c | 10 ++++++++++ > block/blk-ioprio.c | 3 +++ > block/ioprio.c | 3 ++- > block/mq-deadline.c | 1 + > include/linux/ioprio.h | 2 +- > include/uapi/linux/ioprio.h | 7 +++++++ > 6 files changed, 24 insertions(+), 2 deletions(-) > I wonder. _Normally_ a command timeout is only in force once the command is being handed off to the driver. As such it doesn't apply for any scheduling being done before that; most notably the I/O scheduler is not affected by any command timeout. And I was under the impression that CDL really only allows the drive to impose a command timeout on its own. (Pray correct me if I'm mistaken) Hence: does CDL really impinge on the I/O scheduler? Or shouldn't we treat CDL just like a 'normal' command timeout, only to be activated when normal command timeout is enabled? Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), GF: Felix Imendörffer