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 87AF0C43381 for ; Fri, 22 Mar 2019 15:23:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 475022083D for ; Fri, 22 Mar 2019 15:23:22 +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="cOYwYSa3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726703AbfCVPXV (ORCPT ); Fri, 22 Mar 2019 11:23:21 -0400 Received: from mail-it1-f195.google.com ([209.85.166.195]:51518 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726440AbfCVPXV (ORCPT ); Fri, 22 Mar 2019 11:23:21 -0400 Received: by mail-it1-f195.google.com with SMTP id e24so4252803itl.1 for ; Fri, 22 Mar 2019 08:23:21 -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=idTbDdgSVc7JtWlfRBQrCe7voUYIIuq1qsXWuWOqido=; b=cOYwYSa3eBCfnTy0utQlOxD/GS9ptMrq6BQq8w4ulKcIQbUi8ix6yVDfnLwTUUrtUs eL1kBcW16Fxfoc8AXOh9rsh+9UY5I6uLckS371dXfEorYSvvCWWd7n88Sg4JLqEkyBRD 6eyqhN2uDNen9bHhRaFzjM31EKBiLDfmgfHM/C9IdIBDLhhqktR1/OqQShtjC0HQo2zt IKBquE4V0BXRCWGZRyjln4ZaGm7QjrYnFLBqTKPqvCArKAtVc1ZGwOVmu/vIYLvxNLV6 zQTDJg8qpR+TQ6wEoOijdDK85fRRsNQt/RlYYQe+JsEYnO7O7vscIy07jOl59OSkwWbT aFGw== 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=idTbDdgSVc7JtWlfRBQrCe7voUYIIuq1qsXWuWOqido=; b=rPM2V7L9MHXAF7/vZqAsV2EOlWZjPa84DMcoDDHoJlXtCo4T1t4kt3XHZT7ehp0Xyd zkE+fNnkhi7HPLV3zpxCJXV3FZIzHy2yggLrbqv0tl0h2js/K60PlciZEtVs1jITSekP hAl+8CLSGJoXsDAmSyPKd0RYSO/hfLDRxojJC8sD4emprJkIAFYpry3i2qfaYfwfT+AF fqL0OxkkMG28dpq7NtTLEQwAsSgIVDaFJb99DGfOUaskb6qhcCWfDlBX/PN3vOk+kNlh i/cryQXwpk+BHK6Izv8bOlYtZ/IDTwRkVBrhc0y68z4yjOxPg0UerCfr4U3VuQc5OZoA M7Lw== X-Gm-Message-State: APjAAAUrysRM6P2cpFQsroeQUFZiH9sI4GCP2E+dwlBrnfi+KYU/JfRJ DnT5NezKDww9pV7hJku4GHciKireTny6qWLb X-Google-Smtp-Source: APXvYqzviBZgtlY6dc8FCWz3DHq37+p6gHftqyAun3QgPg0pUFEP+E9hfg9uj9iNggUP6TMRqxpVhA== X-Received: by 2002:a02:1c49:: with SMTP id c70mr1527693jac.92.1553268200368; Fri, 22 Mar 2019 08:23:20 -0700 (PDT) Received: from [192.168.1.158] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id m25sm1527428iti.16.2019.03.22.08.23.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Mar 2019 08:23:19 -0700 (PDT) Subject: Re: [PATCH 0/2] blk-mq: convert atomic_t to refcount_t To: Yufen Yu , dwindsor@gmail.com, peterz@infradead.org Cc: linux-block@vger.kernel.org References: <20190322144818.987-1-yuyufen@huawei.com> From: Jens Axboe Message-ID: <24f14149-a309-5876-563c-e11124d0c6ac@kernel.dk> Date: Fri, 22 Mar 2019 09:23:17 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190322144818.987-1-yuyufen@huawei.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 3/22/19 8:48 AM, Yufen Yu wrote: > Hi, > > This patchset covert atomic variables (hctx.nr_active and blk_mq_tag.active_queues) > to newly provided refcount_t type and API, which can prevent accidental counter overflows > and underflows. Neither of these are reference counts in the sense that things go away when they hit zero. -- Jens Axboe