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[73.185.129.58]) by smtp.googlemail.com with ESMTPSA id y18sm12685362ilg.82.2020.03.11.20.10.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 11 Mar 2020 20:10:02 -0700 (PDT) Subject: Re: [PATCH v2 00/17] net: introduce Qualcomm IPA driver (UPDATED) To: Dave Taht Cc: David Miller , Arnd Bergmann , Bjorn Andersson , Andy Gross , Johannes Berg , Dan Williams , Evan Green , Eric Caruso , Susheel Yadav Yadagiri , Chaitanya Pratapa , Subash Abhinov Kasiviswanathan , Rob Herring , Mark Rutland , Ohad Ben-Cohen , Siddharth Gupta , Linux Kernel Network Developers , devicetree@vger.kernel.org, linux-arm-kernel , linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200306042831.17827-1-elder@linaro.org> From: Alex Elder Message-ID: Date: Wed, 11 Mar 2020 22:09:56 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: 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 3/9/20 11:54 AM, Dave Taht wrote: > I am happy to see this driver upstream. > >> Arnd's concern was that the rmnet_data0 network device does not >> have the benefit of information about the state of the underlying >> IPA hardware in order to be effective in controlling TX flow. >> The feared result is over-buffering of TX packets (bufferbloat). >> I began working on some simple experiments to see whether (or how >> much) his concern was warranted. But it turned out that completing >> these experiments was much more work than had been hoped. > > Members of the bufferbloat project *care*, and have tools and testbeds for > exploring these issues. It would be good to establish a relationship with > the vendor, obtain hardware, and other (technical and financial) support, if > possible. > > Is there any specific hardware now available (generally or in beta) that > can be obtained by us to take a harder look? A contact at linaro or QCA > willing discuss options? There exists some hardware that could be used, but at the moment I have not ported this code to operate on it. It is a current effort however, and I will be glad to keep you in the loop on progress. There are a couple of target environments we'd like to support but until last week the primary goal was inclusion in the upstream tree. I will follow up with you after the dust settles a little bit with this patch series, maybe in a week or so. In the mean time I'll also find out whether there are any other resources (people and/or hardware) available. -Alex