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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 24DE2C04AB6 for ; Fri, 31 May 2019 15:37:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04F99218D1 for ; Fri, 31 May 2019 15:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726531AbfEaPhm (ORCPT ); Fri, 31 May 2019 11:37:42 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:38713 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726037AbfEaPhm (ORCPT ); Fri, 31 May 2019 11:37:42 -0400 Received: by mail-pg1-f195.google.com with SMTP id v11so4249028pgl.5; Fri, 31 May 2019 08:37:41 -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=GYc1gNT1Xe9N3fTCA8MDQH9AU47pfIUOquAhYDNc18I=; b=mpL0KmP7NG4T4j/WafbPOfo0Q+k3KwqACmzmhcs+hsC7Uv/k6u0vkZ2ZRiohLAyLod xO/tcUMlWei5pQ4TQdUFuujFYUL9xzVbBRnLr2bpb5Q3DSMO4xrovFKaknycPzVo1TqJ Hx+jotoVVVH4hxNwS4Ways7iDaeTMp6FTsgbFb7+uqLWe5wi0AABzbrrVO0thhdaffEM yzKYzLrQQRizT5eMbkGUMckhyyY79uW1mrgp1zUBYS/wt1frWw2SAeWlmROZTiRIFKeg KqqAL8ClO84ThnDcxIFyb++rn2aoLekliXmxH5Hwg/KgJa0DAc1Wsd1QnmWp+Qm5X+A5 cH4g== X-Gm-Message-State: APjAAAW1VoPUxkgwqok9vwQumla/DMxWw5fPoyDjc+ZCSLut4UvceOzF LxBKvrhHd38rSkxE26QLYMM= X-Google-Smtp-Source: APXvYqzLZfkFMT5ikwvb/uIBEwiRnxzcn5Mx3p6yryK4GXrt7HIRr5nAzFlxut2dsZAuGFeOotaUOw== X-Received: by 2002:a17:90a:fa09:: with SMTP id cm9mr10066010pjb.137.1559317061195; Fri, 31 May 2019 08:37:41 -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 u1sm6509024pfh.85.2019.05.31.08.37.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 31 May 2019 08:37:40 -0700 (PDT) Subject: Re: [PATCH 1/9] blk-mq: allow hw queues to share hostwide tags To: Ming Lei , Jens Axboe , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: James Bottomley , Hannes Reinecke , John Garry , Don Brace , Kashyap Desai , Sathya Prakash , Christoph Hellwig References: <20190531022801.10003-1-ming.lei@redhat.com> <20190531022801.10003-2-ming.lei@redhat.com> From: Bart Van Assche Message-ID: <90d85b99-3bc0-fb3b-8537-aeac03414eae@acm.org> Date: Fri, 31 May 2019 08:37:39 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190531022801.10003-2-ming.lei@redhat.com> 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 5/30/19 7:27 PM, Ming Lei wrote: > diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c > index 6aea0ebc3a73..3d6780504dcb 100644 > --- a/block/blk-mq-debugfs.c > +++ b/block/blk-mq-debugfs.c > @@ -237,6 +237,7 @@ static const char *const alloc_policy_name[] = { > static const char *const hctx_flag_name[] = { > HCTX_FLAG_NAME(SHOULD_MERGE), > HCTX_FLAG_NAME(TAG_SHARED), > + HCTX_FLAG_NAME(HOST_TAGS), > HCTX_FLAG_NAME(BLOCKING), > HCTX_FLAG_NAME(NO_SCHED), > }; The name BLK_MQ_F_HOST_TAGS suggests that tags are shared across a SCSI host. That is misleading since this flag means that tags are shared across hardware queues. Additionally, the "host" term is a term that comes from the SCSI world and this patch is a block layer patch. That makes me wonder whether another name should be used to reflect that all hardware queues share the same tag set? How about renaming BLK_MQ_F_TAG_SHARED into BLK_MQ_F_TAG_QUEUE_SHARED and renaming BLK_MQ_F_HOST_TAGS into BLK_MQ_F_TAG_HCTX_SHARED? Bart.