Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp110948imu; Mon, 10 Dec 2018 17:17:41 -0800 (PST) X-Google-Smtp-Source: AFSGD/V7DmulW0j2GgDLa82xPhmP826Q/siiKpyagw4tnmKTv222+U/uN6/4E4RwhcLwzH6+HD3U X-Received: by 2002:a62:5793:: with SMTP id i19mr14603305pfj.49.1544491061309; Mon, 10 Dec 2018 17:17:41 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1544491061; cv=none; d=google.com; s=arc-20160816; b=uN1rJdVcWVl3cH1o0CsQ4dLEnr9aicm6eoEqOS8+ZzPHDMESlqs3QFkYYmSqypuUAr fe8dmGrsSPrSTEiRG/qm42+oX2y4ZVzhd+WNZXqXpZMJECbxE8vqkcpzkwgO8JSdklPs MLI66grIcAx0yHX+malgX3iFEN9+0sIjX3o2A0N8b5UCVin+1TjSRewJS7iSFCuGsRDK NW8oc9KBi5YuyS09iV5spsOirfdpCb5sfeTHXwl+ObqRArZ4GqgwTd2Dn79LQ4izLVEt L6An4XcLRI+KOJWDMCP+yw1EBYiFc077cPxkUa0wozct8QuCYuv4xYxIrU7VY+BPp2bf CfNg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:dkim-signature; bh=Q/LNkITI6Mo00J9iVRX70fKCzr1sV4kHJirNir7Hw5E=; b=FcRCjsaJADUB7zH8ehhAPsoQDSLZS3X/ShrUtGIXig6lZ0RuPwi5KyZQl8321sOPAh 53JLXa3LCsIDthJfRuN1PqM0Z6Fns9d4vfgQNQreJIrcU3bfOXBtJiL1sitR3Zuc+BxI 3ud+xPr6o7jNSv/qBeEy6wmC9LVC2OCNRYgFTkAKbbvbawn51jAqSwzpix1n0jOp9nso ePnDGL9wlRezRF1b//IPum/TxMQF/2ljmuXdd2MFJaU+pbuXcfvzOv+l0sbJ9vL3GX// OmSrpKOpzWUHOiDSRMEDIpt7oq1YGa4uUHspysaEK9QVsCNV0oS9Kb52uLs5RP0Ubu0F 8zQA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel-dk.20150623.gappssmtp.com header.s=20150623 header.b=iXyAFh3E; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id w61si11277465plb.309.2018.12.10.17.17.26; Mon, 10 Dec 2018 17:17:41 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel-dk.20150623.gappssmtp.com header.s=20150623 header.b=iXyAFh3E; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728168AbeLJVoo (ORCPT + 99 others); Mon, 10 Dec 2018 16:44:44 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:35040 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726562AbeLJVon (ORCPT ); Mon, 10 Dec 2018 16:44:43 -0500 Received: by mail-pf1-f196.google.com with SMTP id z9so6037996pfi.2 for ; Mon, 10 Dec 2018 13:44:43 -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=Q/LNkITI6Mo00J9iVRX70fKCzr1sV4kHJirNir7Hw5E=; b=iXyAFh3E3oigxUa5uYeSGAQCGcrf13cPQEJBqIBuI9upstTBdM5bP2igSIoanHfjv2 XZhpulwOxUuNq+Z5B2ZOQ6peURFOeItO3fOgBcjrN/4KwlHVHfgKG9YmAI0J6MabzxVg LKoags1R4zDMIxOkBWiBM18Vya7OdqSXHu1gJ2qtxTHxmMkxkWIyS7GxNA8HV4liqXPL SVKOtcr3EUlmJjYiZkNQnyAOmvSCpKZJ38o4Ee/X8OTDY+o9+BQ3svPe0cHYP1sYK/H8 yYIKit/AoJ26+6d6teoCtl0I+mQowr3x0infaTdR7KAVXuRWGbWEpOslqdMZB25rGfq9 bxuQ== 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=Q/LNkITI6Mo00J9iVRX70fKCzr1sV4kHJirNir7Hw5E=; b=q3P0Kcd79CLXbWaKUpWNCDvHOl2jQ4xqn/dfbVWtMBlyPby7I7Oh+DQb4TcsW+tgcK bTYvbBXQxrIPCo4v+iM5MV4EYnhRTaP/47Tsfd8X+K2vHBm0LOrlRBiCc/PNAlb+V+O9 UvL301T4HuM1+DUsdJnY3RVjeaZQ5Sxu2Pv0nUs+GjjL+O29YB+REtd9tBmL/heR/cnR zK7w5N5PpQldSjA7Xqz5cYacMPvfZ36ZMNgyR2caaRrYKJ9L+eB2p1V1HzpyqkmOgVvX vkRnbq2dIFd5dUxeintK7PyTv9V1m+wEqr9jEsC6c4MD/OEA/AI8KP2vxF+i96SV0vTW B/0w== X-Gm-Message-State: AA+aEWaxfdvtldatG1j8nTb2ZDG+lGwdTkjqBo9MCHPOZpkxOrwJGvH9 bxx0og60EvrwOvkNYp4KI9T/+V7xMrwbSw== X-Received: by 2002:a63:bd1a:: with SMTP id a26mr12159678pgf.121.1544478282281; Mon, 10 Dec 2018 13:44:42 -0800 (PST) Received: from [192.168.1.121] (66.29.188.166.static.utbb.net. [66.29.188.166]) by smtp.gmail.com with ESMTPSA id 64sm16187094pff.101.2018.12.10.13.44.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 10 Dec 2018 13:44:41 -0800 (PST) Subject: Re: [PATCH] mtip32xx: avoid using semaphores To: Arnd Bergmann Cc: Johannes Thumshirn , Hannes Reinecke , Bart Van Assche , Matthew Wilcox , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20181210213459.1147671-1-arnd@arndb.de> From: Jens Axboe Message-ID: <6caf6fa4-15e5-a7ec-cec4-69e5ad70c090@kernel.dk> Date: Mon, 10 Dec 2018 14:44:39 -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: <20181210213459.1147671-1-arnd@arndb.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/10/18 2:34 PM, Arnd Bergmann wrote: > The "cmd_slot_unal" semaphore is never used in a blocking way > but only as an atomic counter. Change the code to using > atomic_dec_if_positive() as a better API. Looks good to me. We should also convert the return to blk-mq when we hit failure here to BLK_STS_DEV_RESOURCE, but that's a separate patch. -- Jens Axboe