From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by yocto-www.yoctoproject.org (Postfix, from userid 118) id B5A7FE00945; Wed, 11 Feb 2015 19:50:25 -0800 (PST) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on yocto-www.yoctoproject.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 X-Spam-HAM-Report: * -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, * medium trust * [147.11.146.13 listed in list.dnswl.org] * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] Received: from mail1.windriver.com (mail1.windriver.com [147.11.146.13]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 2F444E0093B; Wed, 11 Feb 2015 19:50:16 -0800 (PST) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail1.windriver.com (8.14.9/8.14.5) with ESMTP id t1C3oCDt005706 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Wed, 11 Feb 2015 19:50:12 -0800 (PST) Received: from server.local (128.224.22.243) by ALA-HCA.corp.ad.wrs.com (147.11.189.40) with Microsoft SMTP Server id 14.3.174.1; Wed, 11 Feb 2015 19:50:12 -0800 Message-ID: <54DC22F3.9030805@windriver.com> Date: Wed, 11 Feb 2015 22:50:11 -0500 From: Bruce Ashfield User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: William Mills , Stephen Flowers , , References: <54DA0258.9070108@gmail.com> <54DA12C7.8000000@windriver.com> <54DA84F1.1080109@gmail.com> <54DADD75.5000809@windriver.com> <54DB17E7.8070308@gmail.com> <54DB7455.4020402@windriver.com> <54DBF55D.3020001@ti.com> In-Reply-To: <54DBF55D.3020001@ti.com> Subject: Re: Yocto Realtime tests on beaglebone black X-BeenThere: yocto@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Discussion of all things Yocto Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Feb 2015 03:50:25 -0000 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit On 2015-02-11 7:35 PM, William Mills wrote: > + meta-ti > Please keep meta-ti in the loop. > > [Sorry for the shorting. Thunderbird keep locking up when I tried > replay all in plain text to this message.] Heh. I know the pain, the giant .configs can give it a fit. > > ~ 15-02-11, Stephen Flowers wrote: > > Thanks for your input. Here are results of 1000 samples over a > > 10 second period: > > > > Interrupt response (microseconds) > > standard: min: 81, max:118, average: 84 > > rt: min: 224, max: 289, average: 231 > > > >Will share the .config later once I get on that machine. > > Steve I agree the numbers look strange. > There may well be something funny for RT going on for BBB. > TI is just starting to look into RT for BBB. > > I would like to see the cyclictest results under heavy system load for > standard and RT kernels. The whole point of RT is to limit the max > latency when the system is doing *anything*. > > I am not surprised that the standard kernel has good latency when idle. > As you add load (filessystem is usually a good load) you should see that > max goes up a lot. > > Also, as Bruce says, some degradation of min and average and also > general system throughput is expected for RT. That is the trade-off. > I still think the number you are getting for RT seem high but I don't > know what your test is doing in detail. (I did read your explanation.) > cyclictest should give us a standard baseline. Agreed. Bruce > > > On 02/11/2015 10:25 AM, Bruce Ashfield wrote: >> On 15-02-11 03:50 AM, Stephen Flowers wrote: >>> >>> my bad, here is the patch set. >>> As for load, only system idle load for the results I posted previously. >>> Will run some cyclic test next. >> >> One thing that did jump out was the difference in config_hz, you >> are taking a lot more ticks in the preempt-rt configuration. If >> you run both at the same hz, or with no_hz enabled, it would be >> interesting to see if there's a difference. >> >> Bruce From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by yocto-www.yoctoproject.org (Postfix, from userid 118) id B5A7FE00945; Wed, 11 Feb 2015 19:50:25 -0800 (PST) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on yocto-www.yoctoproject.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 X-Spam-HAM-Report: * -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, * medium trust * [147.11.146.13 listed in list.dnswl.org] * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] Received: from mail1.windriver.com (mail1.windriver.com [147.11.146.13]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 2F444E0093B; Wed, 11 Feb 2015 19:50:16 -0800 (PST) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail1.windriver.com (8.14.9/8.14.5) with ESMTP id t1C3oCDt005706 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Wed, 11 Feb 2015 19:50:12 -0800 (PST) Received: from server.local (128.224.22.243) by ALA-HCA.corp.ad.wrs.com (147.11.189.40) with Microsoft SMTP Server id 14.3.174.1; Wed, 11 Feb 2015 19:50:12 -0800 Message-ID: <54DC22F3.9030805@windriver.com> Date: Wed, 11 Feb 2015 22:50:11 -0500 From: Bruce Ashfield User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: William Mills , Stephen Flowers , , References: <54DA0258.9070108@gmail.com> <54DA12C7.8000000@windriver.com> <54DA84F1.1080109@gmail.com> <54DADD75.5000809@windriver.com> <54DB17E7.8070308@gmail.com> <54DB7455.4020402@windriver.com> <54DBF55D.3020001@ti.com> In-Reply-To: <54DBF55D.3020001@ti.com> X-Mailman-Approved-At: Fri, 13 Feb 2015 07:49:53 -0800 Subject: Re: [yocto] Yocto Realtime tests on beaglebone black X-BeenThere: meta-ti@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Usage and development list for the meta-ti layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Feb 2015 03:50:25 -0000 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit On 2015-02-11 7:35 PM, William Mills wrote: > + meta-ti > Please keep meta-ti in the loop. > > [Sorry for the shorting. Thunderbird keep locking up when I tried > replay all in plain text to this message.] Heh. I know the pain, the giant .configs can give it a fit. > > ~ 15-02-11, Stephen Flowers wrote: > > Thanks for your input. Here are results of 1000 samples over a > > 10 second period: > > > > Interrupt response (microseconds) > > standard: min: 81, max:118, average: 84 > > rt: min: 224, max: 289, average: 231 > > > >Will share the .config later once I get on that machine. > > Steve I agree the numbers look strange. > There may well be something funny for RT going on for BBB. > TI is just starting to look into RT for BBB. > > I would like to see the cyclictest results under heavy system load for > standard and RT kernels. The whole point of RT is to limit the max > latency when the system is doing *anything*. > > I am not surprised that the standard kernel has good latency when idle. > As you add load (filessystem is usually a good load) you should see that > max goes up a lot. > > Also, as Bruce says, some degradation of min and average and also > general system throughput is expected for RT. That is the trade-off. > I still think the number you are getting for RT seem high but I don't > know what your test is doing in detail. (I did read your explanation.) > cyclictest should give us a standard baseline. Agreed. Bruce > > > On 02/11/2015 10:25 AM, Bruce Ashfield wrote: >> On 15-02-11 03:50 AM, Stephen Flowers wrote: >>> >>> my bad, here is the patch set. >>> As for load, only system idle load for the results I posted previously. >>> Will run some cyclic test next. >> >> One thing that did jump out was the difference in config_hz, you >> are taking a lot more ticks in the preempt-rt configuration. If >> you run both at the same hz, or with no_hz enabled, it would be >> interesting to see if there's a difference. >> >> Bruce