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 X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD1A6C433E0 for ; Wed, 24 Feb 2021 06:55:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C29164DAF for ; Wed, 24 Feb 2021 06:55:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234292AbhBXGzQ (ORCPT ); Wed, 24 Feb 2021 01:55:16 -0500 Received: from mx2.suse.de ([195.135.220.15]:45832 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234218AbhBXGyy (ORCPT ); Wed, 24 Feb 2021 01:54:54 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 084EBAE3C; Wed, 24 Feb 2021 06:54:13 +0000 (UTC) Subject: Re: [PATCHv7 00/31] scsi: enable reserved commands for LLDDs To: John Garry , "Martin K. Petersen" Cc: James Bottomley , Christoph Hellwig , linux-scsi@vger.kernel.org, "Viswas.G@microchip.com" References: <20210222132405.91369-1-hare@suse.de> <6d2f5677-b033-9639-82da-655152ad6d8c@huawei.com> From: Hannes Reinecke Message-ID: Date: Wed, 24 Feb 2021 07:54:11 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <6d2f5677-b033-9639-82da-655152ad6d8c@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 2/23/21 6:50 PM, John Garry wrote: > On 23/02/2021 10:16, John Garry wrote: >> On 22/02/2021 13:23, Hannes Reinecke wrote: >>> Hi all, >> >> + >> >>> >>> quite some drivers use internal commands for various purposes, most >>> commonly sending TMFs or querying the HBA status. >>> While these commands use the same submission mechanism than normal >>> I/O commands, they will not be counted as outstanding commands, >>> requiring those drivers to implement their own mechanism to figure >>> out outstanding commands. >>> The block layer already has the concept of 'reserved' tags for >>> precisely this purpose, namely non-I/O tags which live off a separate >>> tag pool. That guarantees that these commands can always be sent, >>> and won't be influenced by tag starvation from the I/O tag pool. >>> This patchset enables the use of reserved tags for the SCSI midlayer >>> by allocating a virtual LUN for the HBA itself which just serves >>> as a resource to allocate valid tags from. >>> This removes quite some hacks which were required for some >>> drivers (eg. fnic or snic), and allows the use of tagset >>> iterators within the drivers. >>> >>> The entire patchset can be found at >>> >>> git://git.kernel.org/pub/scm/linux/kernel/git/hare/scsi-devel.git >>> reserved-tags.v7 >> >> >> Thanks for doing this, I'll have a look. > > So I got this working eventually for hisi_sas - a few fixes needed: > https://github.com/hisilicon/kernel-dev/commits/private-topic-sas-5.11-resv7 > > > I'll have a look at the core patches tomorrow. However, at this point, > how about convert just a couple of drivers (the ones which you can test) > to get it merged as a start? 31 patches is too many. > Yeah, I know. Actually, I just sent it out so that you can have a look at my libsas slow task rework. But I can easily split it off for just fnic/snic/aacraid/hpsa, and leave the libsas slow task stuff for the next round. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer