From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by yocto-www.yoctoproject.org (Postfix, from userid 118) id DDBBDE00824; Thu, 12 Feb 2015 14:05:21 -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=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-HAM-Report: * 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider * (sflowers1[at]gmail.com) * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's * domain * 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily * valid * -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature * -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low * trust * [209.85.212.176 listed in list.dnswl.org] Received: from mail-wi0-f176.google.com (mail-wi0-f176.google.com [209.85.212.176]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 3EB4DE00546; Thu, 12 Feb 2015 14:05:19 -0800 (PST) Received: by mail-wi0-f176.google.com with SMTP id h11so7805192wiw.3; Thu, 12 Feb 2015 14:05:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=Lzo4+ESdPEqXNkYwAq4JWjCPljG+WMxa4q8IXengzYQ=; b=ov7DFdAgkQlfH/JNT/JRbwToup5dSEfD32ipJuUNfhDIQ1sDeWI+pGPTsU6ivKf7gg NSBAnnLx42R6FNI84AfXbybQBC/RyVKBjXX2XiyHIk9NPdtdeegZ3aqAx394hJ/5MF9P 0VqfJQMBf+bnFnPMveUjfse2CfHhYLtKnmTOd2NioM2/XXagoUFcJAn6OdCSiDTXjj9X +0fTKwx725q2jzyr+xFJ8e6fj6QDaPoax90yuLsavepGSJYEnNU661ZiyDGiBzSgW7Ar r6Nh87Ew9OnOqJo9xWTInXkBwC5FMbBIpd50GU121WD9ekCjDAL086DOVei67T6sILH5 ksOQ== X-Received: by 10.180.73.241 with SMTP id o17mr846959wiv.16.1423778718518; Thu, 12 Feb 2015 14:05:18 -0800 (PST) Received: from [192.168.0.5] ([2.123.59.41]) by mx.google.com with ESMTPSA id ha1sm220193wib.24.2015.02.12.14.05.17 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 12 Feb 2015 14:05:17 -0800 (PST) Message-ID: <54DD2396.4000909@gmail.com> Date: Thu, 12 Feb 2015 22:05:10 +0000 From: Stephen Flowers User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: William Mills , Bruce Ashfield , yocto@yoctoproject.org, meta-ti@yoctoproject.org 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 22:05:21 -0000 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit So I ran cyclictest with an idle system and loaded with multiple instances of cat /dev/zero > /dev/null & #cyclictest -a 0 -p 99 -m -n -l 100000 -q I ran this command as shown by Toyoka at the 2014 Linuxcon Japan [http://events.linuxfoundation.org/sites/events/files/slides/toyooka_LCJ2014_v10.pdf] to compare against his results for the BBB. I also threw in xenomai with kernel 3.8 for comparison. For the standard kernel HR timers were disabled. [idle] preempt_rt: min 12 avg: 20 max: 59 standard: min: 8005 avg: 309985955 max: 619963985 xenomai: min: 8 avg: 16: max 803 [loaded] preempt_rt: min 16 avg: 21 max: 47 standard: min: 15059 avg: 67769851 max: 135530885 xenomai: min: 10 avg: 15: max 839 Actually the preempt_rt results tie up pretty well with Toyooka above, leading me to conclude theres something off in my code that could be optimised - what do you guys think. Also, I ran a test with preempt_rt at 100Hz and there was maybe 10% improvement in latency. Steve On 12/02/2015 00:35, 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.] > > ~ 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. > > > 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 DDBBDE00824; Thu, 12 Feb 2015 14:05:21 -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=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-HAM-Report: * 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider * (sflowers1[at]gmail.com) * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's * domain * 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily * valid * -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature * -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low * trust * [209.85.212.176 listed in list.dnswl.org] Received: from mail-wi0-f176.google.com (mail-wi0-f176.google.com [209.85.212.176]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 3EB4DE00546; Thu, 12 Feb 2015 14:05:19 -0800 (PST) Received: by mail-wi0-f176.google.com with SMTP id h11so7805192wiw.3; Thu, 12 Feb 2015 14:05:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=Lzo4+ESdPEqXNkYwAq4JWjCPljG+WMxa4q8IXengzYQ=; b=ov7DFdAgkQlfH/JNT/JRbwToup5dSEfD32ipJuUNfhDIQ1sDeWI+pGPTsU6ivKf7gg NSBAnnLx42R6FNI84AfXbybQBC/RyVKBjXX2XiyHIk9NPdtdeegZ3aqAx394hJ/5MF9P 0VqfJQMBf+bnFnPMveUjfse2CfHhYLtKnmTOd2NioM2/XXagoUFcJAn6OdCSiDTXjj9X +0fTKwx725q2jzyr+xFJ8e6fj6QDaPoax90yuLsavepGSJYEnNU661ZiyDGiBzSgW7Ar r6Nh87Ew9OnOqJo9xWTInXkBwC5FMbBIpd50GU121WD9ekCjDAL086DOVei67T6sILH5 ksOQ== X-Received: by 10.180.73.241 with SMTP id o17mr846959wiv.16.1423778718518; Thu, 12 Feb 2015 14:05:18 -0800 (PST) Received: from [192.168.0.5] ([2.123.59.41]) by mx.google.com with ESMTPSA id ha1sm220193wib.24.2015.02.12.14.05.17 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 12 Feb 2015 14:05:17 -0800 (PST) Message-ID: <54DD2396.4000909@gmail.com> Date: Thu, 12 Feb 2015 22:05:10 +0000 From: Stephen Flowers User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: William Mills , Bruce Ashfield , yocto@yoctoproject.org, meta-ti@yoctoproject.org 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 22:05:21 -0000 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit So I ran cyclictest with an idle system and loaded with multiple instances of cat /dev/zero > /dev/null & #cyclictest -a 0 -p 99 -m -n -l 100000 -q I ran this command as shown by Toyoka at the 2014 Linuxcon Japan [http://events.linuxfoundation.org/sites/events/files/slides/toyooka_LCJ2014_v10.pdf] to compare against his results for the BBB. I also threw in xenomai with kernel 3.8 for comparison. For the standard kernel HR timers were disabled. [idle] preempt_rt: min 12 avg: 20 max: 59 standard: min: 8005 avg: 309985955 max: 619963985 xenomai: min: 8 avg: 16: max 803 [loaded] preempt_rt: min 16 avg: 21 max: 47 standard: min: 15059 avg: 67769851 max: 135530885 xenomai: min: 10 avg: 15: max 839 Actually the preempt_rt results tie up pretty well with Toyooka above, leading me to conclude theres something off in my code that could be optimised - what do you guys think. Also, I ran a test with preempt_rt at 100Hz and there was maybe 10% improvement in latency. Steve On 12/02/2015 00:35, 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.] > > ~ 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. > > > 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