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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D2ADCC4360C for ; Thu, 26 Sep 2019 15:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAEEA21A4A for ; Thu, 26 Sep 2019 15:01:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725917AbfIZPBN (ORCPT ); Thu, 26 Sep 2019 11:01:13 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:34594 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725813AbfIZPBN (ORCPT ); Thu, 26 Sep 2019 11:01:13 -0400 Received: by mail-pg1-f196.google.com with SMTP id y35so1746906pgl.1; Thu, 26 Sep 2019 08:01:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=V6OEDSg3Eh3+cw9Wul3ZcjAozpdG82PaFBx486g+mfI=; b=Zk2AGYfZzA9wIIcaKbkFIZmYPGLMycZHwl3ee4WPQfg/I6UWJW11fxcAXFRD3vIQ3K JggD5cAiRkNARCDexJQPf3LTmFCPXp1hjnyjScfRqMZ5gETdKCvkH6eyBGBBnAnNJeH8 zy2WNu1g8iEbtn3aeM3iwzuULUFR/rYJRUC5lBxcCKyaSA7DpSzTTr3dQOCT1bOyor1Z 0Xvd8Lj+q+PwZSNcx0RVQtqTmSLfFU2/U1wmHb8jNTsEM2y/idolD2hjQhUdCBHyFSlM V1clcmv+3X+5mZRCitrw569e9ZfOxlKSL/pXYlozIdjXqBVSlhxEWBGeKpUkQqyvwRBd IK/Q== X-Gm-Message-State: APjAAAVPWvi3NxoKmZ44Fagb1DPqLc3kqmv9Vpan+n8sc68nSfrWKe15 8BuvXQvreXuYVTSOLRcyKZY= X-Google-Smtp-Source: APXvYqyCKN9e4LROHfH5S/SbBSnZweni4d/qbumk7xMjpF9CmZlAsmvtvGxv+1PHVmXmjwBfptijsA== X-Received: by 2002:a17:90a:3086:: with SMTP id h6mr4052819pjb.1.1569510072170; Thu, 26 Sep 2019 08:01:12 -0700 (PDT) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id bb15sm2184066pjb.2.2019.09.26.08.01.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Sep 2019 08:01:11 -0700 (PDT) Subject: Re: [PATCH v4 17/25] ibnbd: client: main functionality To: Roman Penyaev , Danil Kipnis Cc: Jack Wang , linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, Jens Axboe , Christoph Hellwig , Sagi Grimberg , Jason Gunthorpe , Doug Ledford , rpenyaev@suse.de, Jack Wang References: <20190620150337.7847-1-jinpuwang@gmail.com> <20190620150337.7847-18-jinpuwang@gmail.com> <5c5ff7df-2cce-ec26-7893-55911e4d8595@acm.org> <6f677d56-82b3-a321-f338-cbf8ff4e83eb@acm.org> From: Bart Van Assche Message-ID: Date: Thu, 26 Sep 2019 08:01:09 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 9/26/19 2:55 AM, Roman Penyaev wrote: > As I remember correctly I could not reuse the whole machinery with those > restarts from block core because shared tags are shared only between > hardware queues, i.e. different hardware queues share different tags sets. > IBTRS has many hardware queues (independent RDMA connections) but only one > tags set, which is equally shared between block devices. What I dreamed > about is something like BLK_MQ_F_TAG_GLOBALLY_SHARED support in block > layer. A patch series that adds support for sharing tag sets across hardware queues is pending. See also "[PATCH V3 0/8] blk-mq & scsi: fix reply queue selection and improve host wide tagset" (https://lore.kernel.org/linux-block/20180227100750.32299-1-ming.lei@redhat.com/). Would that patch series allow to remove the queue management code from ibnbd? Thanks, Bart.