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[70.175.137.120]) by smtp.gmail.com with ESMTPSA id 198sm5083332pfu.32.2021.08.04.23.14.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Aug 2021 23:14:56 -0700 (PDT) Subject: Re: [PATCH v2 3/3] loop: Add the default_queue_depth kernel module parameter To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , Jaegeuk Kim , Ming Lei , Tetsuo Handa , Martijn Coenen References: <20210803182304.365053-1-bvanassche@acm.org> <20210803182304.365053-4-bvanassche@acm.org> From: Chaitanya Kulkarni Message-ID: <2971a1f5-08c1-a6e2-3125-abfc2e13d63d@gmail.com> Date: Wed, 4 Aug 2021 23:14:56 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 8/3/2021 11:07 PM, Greg KH wrote: > On Tue, Aug 03, 2021 at 11:23:04AM -0700, Bart Van Assche wrote: >> Recent versions of Android use the zram driver on top of the loop driver. >> There is a mismatch between the default loop driver queue depth (128) and >> the queue depth of the storage device in my test setup (32). That mismatch >> results in write latencies that are higher than necessary. Address this >> issue by making the default loop driver queue depth configurable. Compared >> to configuring the queue depth by writing into the nr_requests sysfs >> attribute, this approach does not involve calling synchronize_rcu() to >> modify the queue depth. >> >> Reviewed-by: Ming Lei >> Cc: Tetsuo Handa >> Cc: Christoph Hellwig >> Cc: Martijn Coenen >> Cc: Jaegeuk Kim >> Signed-off-by: Bart Van Assche If I remember correct I've sent patch based on the similar concept that is not entirely different than this one. -- -ck