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=-1.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 B7E09C64EB1 for ; Thu, 6 Dec 2018 15:22:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CC0220868 for ; Thu, 6 Dec 2018 15:22:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="a5/TS7rF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CC0220868 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726074AbeLFPWX (ORCPT ); Thu, 6 Dec 2018 10:22:23 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:40637 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725871AbeLFPWW (ORCPT ); Thu, 6 Dec 2018 10:22:22 -0500 Received: by mail-it1-f196.google.com with SMTP id h193so1973247ita.5 for ; Thu, 06 Dec 2018 07:22:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=OIcNE0qExtQ7XdOd9lxbE8Pm9ZafrOGEfrkAmfXOOSQ=; b=a5/TS7rFWB/BXzyHu6XBKlE7o4Rj+cSA7gRV3F+wBzhdnecNBjjQ6S791NNCxDzs/W uA+peGx6+D29VCtwDE/1mqwDUiK3W4kohdh5hjDDwdejqnH/K5BcBA82c6vk+Q97yWZa Fz9N17HTlJYFQ44qSeot2E27nyQvy8Br6LLtu+vhj8ixC7MSYEwDI+0eXxDhYU+X1vJr l8zjHijqNljrI3/Zaej66r9lbof3XBBVY+d2DV8v6r2qHTDfV5M7xjfMxehyJlTLilLu TgkW7wceUvscPSJeK/veSWOfxuhd8SxhXCTOKquYKCTfK7lVQAep+0mtELN3KRJLBPDE uwqA== 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=OIcNE0qExtQ7XdOd9lxbE8Pm9ZafrOGEfrkAmfXOOSQ=; b=k1FVoFW1gwv+MQJaNuyU2W2J5PlZM20l4l2nhHmhxKf+TCT0XkPs1XWzJoCSSeL8a+ XkSQ8cFqYCl7RsVYqfeVcY04HZnk7y27dzQnec8PwlXS6AfFaQ8MXNbdnrW8RDZJjK09 xKxvpVWARArIFeiHTVgfBHW6k0r48Ssy+IpXyuqQQXfjViPYDgjnR9vkiJ+Nhd+Pld7V fDpe7mRwJVR27DyKC4ZAa+zfPgmbLuSS2SK8NGrBwu+Tb2b/zxc6qmw0UtLWQUAKGsTn t0kvifrJlCpNuXCtcbrWkIdicwQa9ukIpCSxZ1XxmcnHqxb8QA8IYsCfBlZnoxu5N1IG oOsg== X-Gm-Message-State: AA+aEWYHbxlomg7HW6POSR4vNYw0vP4/9MRt8AWApgZDwgtMOvAXrGzM 8zXpLZxyEIhy36Gm6zPcuS6MCA== X-Google-Smtp-Source: AFSGD/UAC3s+ssKun+IvKkHjkvfU+IyNa6u8cW9BeCN9HyDSGoBmN/TNG9b6IqV8ObyiiZLjiz6V5A== X-Received: by 2002:a24:9005:: with SMTP id x5mr18420978itd.102.1544109741218; Thu, 06 Dec 2018 07:22:21 -0800 (PST) Received: from [192.168.1.56] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id i78sm523834itb.6.2018.12.06.07.22.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Dec 2018 07:22:20 -0800 (PST) Subject: Re: +AFs-PATCH+AF0- blk-mq: Set request mapping to NULL in blk+AF8-mq+AF8-put+AF8-driver+AF8-tag To: Kashyap Desai , Ming Lei Cc: Bart Van Assche , linux-block , linux-scsi , Suganath Prabu Subramani , Sreekanth Reddy , Sathya Prakash Veerichetty References: <1543943674.185366.194.camel@acm.org> <20181206003323.GB3015@ming.t460p> <9e57309d7f40c35c1096b6f932c02f68@mail.gmail.com> From: Jens Axboe Message-ID: Date: Thu, 6 Dec 2018 08:22:18 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <9e57309d7f40c35c1096b6f932c02f68@mail.gmail.com> Content-Type: text/plain; charset=utf-8 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 12/5/18 10:45 PM, Kashyap Desai wrote: >> >> If the 'tag' passed to scsi_host_find_tag() is valid, I think there >> shouldn't have such issue. >> >> If you want to find outstanding IOs, maybe you can try >> blk_mq_queue_tag_busy_iter() >> or blk_mq_tagset_busy_iter(), because you may not know if the passed > 'tag' >> to >> scsi_host_find_tag() is valid or not. > > We tried quick change in mpt3sas driver using blk_mq_tagset_busy_iter and > it returns/callback for valid requests (no stale entries are returned). > Expected. > Above two APIs are only for blk-mq. What about non-mq case ? Driver > should use scsi_host_find_tag for non-mq and blk_mq_tagset_busy_iter for > blk-mq case ? > I don't see that will be good interface. Also, blk_mq_tagset_busy_iter API > does not provide control if driver wants to quit in-between or do some > retry logic etc. > > Why can't we add single API which provides the correct output. >From 4.21 and forward, there will only be blk/scsi-mq. This is exactly the problem with having to maintain two stacks, it's a huge pain. -- Jens Axboe