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[107.191.0.158]) by smtp.gmail.com with ESMTPSA id b195-v6sm2768675itc.42.2018.08.08.07.40.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Aug 2018 07:40:27 -0700 (PDT) Subject: Re: [PATCH V2] blk-mq: count the hctx as active before allocate tag To: Jianchao Wang Cc: tom.leiming@gmail.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <1533722212-20327-1-git-send-email-jianchao.w.wang@oracle.com> From: Jens Axboe Message-ID: Date: Wed, 8 Aug 2018 08:40:26 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <1533722212-20327-1-git-send-email-jianchao.w.wang@oracle.com> 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 8/8/18 3:56 AM, Jianchao Wang wrote: > Currently, we count the hctx as active after allocate driver tag > successfully. The other shared-tags users could exhaust the driver > tags and starve a non-active and waiting-tag hctx. Count the hctx as > active before try to allocate driver tag to fix this. Patch looks good, but please add some comments along the way. -- Jens Axboe