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=-6.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 9B622C43458 for ; Tue, 28 Jul 2020 15:37:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 760832078E for ; Tue, 28 Jul 2020 15:37:57 +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="sFeRSbxr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730800AbgG1Ph4 (ORCPT ); Tue, 28 Jul 2020 11:37:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730678AbgG1Ph4 (ORCPT ); Tue, 28 Jul 2020 11:37:56 -0400 Received: from mail-il1-x144.google.com (mail-il1-x144.google.com [IPv6:2607:f8b0:4864:20::144]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2164AC061794 for ; Tue, 28 Jul 2020 08:37:56 -0700 (PDT) Received: by mail-il1-x144.google.com with SMTP id j9so13167408ilc.11 for ; Tue, 28 Jul 2020 08:37:56 -0700 (PDT) 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=aT/4Vd1KT6gFUEyaURRCi9T5w1JgYeHkaL9/rT+SjdM=; b=sFeRSbxrDGk1FX1/85Qv7FXIlsc76+QGGUWMfOjXNSfVVvdM3ACfzQHLbqezRd6BOd njlEWUrAROEV1+gX5qSdf3MHM7jPnoqMwXb5cEFM2nLDHTljMst2sjQQXNFby+ZwqAhk R5cd4wY1rm3RkLoJTOBDPpBXH7c6O6e7xifxbWYSZm3wPeo3vw+qCfOtEbfezD9F8svX 1Yc25TTk0P+oDj7KTqcj48j3GE2pQDex9QiHSCKk1S1XMJStDKHTqzf/m1s7vEB4GtCh zZDwug/yEN0AG/yuDhhY0es8K3VDnFqkIK+L99us7hibyLuSGo/TdKSPjLUigjTH/6OJ YaNw== 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=aT/4Vd1KT6gFUEyaURRCi9T5w1JgYeHkaL9/rT+SjdM=; b=LikbncSYHU9BELWGn5V1N6xoDxdoIGP+5Nq8ZrAAtdJyf9rr9lpKkjLqKPnQqkPnx9 QuBIcY8Pcc1tZNUjetNqfad/hDMzSpMdO71QAsMkQEiH5+PyFIez3QOJIBW8DXaTCMZC /SAFf0Hl++O6AvLKhbyUGcykmqmHVL8OIRXY+kM5q1z8vjuOR6a7OAuRKPj34gAB/978 dfR7+Fn+YZmHZIfOcGrvMWI0LFoSpvua9eyLXMI+KhxSD+PkZIZBxyXW90YyFUVfmFLG 61SpvuUtWppHLPWWVpImXHkrZSSiKi0fz24JpP8tjJW/D+hP1R37dMDZF79M0EYqbufs X2CA== X-Gm-Message-State: AOAM533vZgxgy1VpSM0mo0SBfyazn+sXm1UiJRMKbyZBG79J7GKWBXiM V4ytzYPNvexRN9qwyCYdL625Xg== X-Google-Smtp-Source: ABdhPJwqrM+TwYM3A0LLl4/nqG8Pt+LJGaycrasyS6nUKhqtbIBby3yzfVH1Ro6mIWoOXWDdYhVouw== X-Received: by 2002:a92:5e1d:: with SMTP id s29mr14577822ilb.245.1595950675515; Tue, 28 Jul 2020 08:37:55 -0700 (PDT) Received: from [192.168.1.58] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id r3sm4772269iov.22.2020.07.28.08.37.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Jul 2020 08:37:55 -0700 (PDT) Subject: Re: [PATCH] block: Use non _rcu version of list functions for tag_set_list To: Daniel Wagner Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Ming Lei References: <20200728132951.29459-1-dwagner@suse.de> From: Jens Axboe Message-ID: <67e31df0-b86c-6a2e-d9da-3e8a7114e42e@kernel.dk> Date: Tue, 28 Jul 2020 09:37:54 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200728132951.29459-1-dwagner@suse.de> 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 7/28/20 7:29 AM, Daniel Wagner wrote: > tag_set_list is only accessed under the tag_set_lock lock. There is > no need for using the _rcu list functions. > > The _rcu list function were introduced to allow read access to the > tag_set_list protected under RCU, see 705cda97ee3a ("blk-mq: Make it > safe to use RCU to iterate over blk_mq_tag_set.tag_list") and > 05b79413946d ("Revert "blk-mq: don't handle TAG_SHARED in restart""). > Those changes got reverted later but the cleanup commit missed a > couple of places to undo the changes. Applied, thanks. -- Jens Axboe