From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <5350E6BE.9080104@mitrol.it> Date: Fri, 18 Apr 2014 10:47:58 +0200 From: Paolo Minazzi MIME-Version: 1.0 References: <5347D5BB.1070107@mitrol.it> <5347D6E0.2030805@xenomai.org> <5347DCCC.3040801@mitrol.it> <5347DF09.9080905@xenomai.org> <5347E0E1.3020807@mitrol.it> <5347E3DA.6010106@xenomai.org> <5347E8AB.7020908@mitrol.it> <5347EB00.7060203@xenomai.org> <534FC6F3.1050305@mitrol.it> <534FD826.8030701@xenomai.org> In-Reply-To: <534FD826.8030701@xenomai.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] arm imx6 and hardware FPU [SOLVED] List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org Il 17/04/2014 15.33, Gilles Chanteperdrix ha scritto: > On 04/17/2014 02:20 PM, Paolo Minazzi wrote: >> Il 11/04/2014 15.15, Gilles Chanteperdrix ha scritto: >>> On 04/11/2014 03:05 PM, Paolo Minazzi wrote: >>>> Il 11/04/2014 14.45, Gilles Chanteperdrix ha scritto: >>>>> On 04/11/2014 02:32 PM, Paolo Minazzi wrote: >>>>>> Il 11/04/2014 14.24, Gilles Chanteperdrix ha scritto: >>>>>>> On 04/11/2014 02:15 PM, Paolo Minazzi wrote: >>>>>>>> Il 11/04/2014 13.49, Gilles Chanteperdrix ha scritto: >>>>>>>>> On 04/11/2014 01:44 PM, Paolo Minazzi wrote: >>>>>>>>>> Hi to all, >>>>>>>>>> I'm trying to test my imx6 with xenomai 2.6.3. >>>>>>>>>> I use the linaro cross-compiler that uses the hardware floating >>>>>>>>>> point. >>>>>>>>>> >>>>>>>>>> I made a simple floating point test. >>>>>>>>>> >>>>>>>>>> If I use two non-realtime user-space tasks the test works OK >>>>>>>>>> and I >>>>>>>>>> have >>>>>>>>>> no errors in calculations. >>>>>>>>>> This means that compiler and hardware works well. >>>>>>>>>> >>>>>>>>>> But I I use two realtime user-space tasks I have errors in >>>>>>>>>> calculations. >>>>>>>>>> Real-time tasks are created with rt_task_create(&demo, >>>>>>>>>> "demo", 0, >>>>>>>>>> 99, >>>>>>>>>> T_FPU); >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> This is my kernel config >>>>>>>>>> ============================================ >>>>>>>>>> ... >>>>>>>>>> # >>>>>>>>>> # Machine >>>>>>>>>> # >>>>>>>>>> CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH=y >>>>>>>>>> CONFIG_IPIPE_WANT_ACTIVE_MM=y >>>>>>>>>> CONFIG_XENO_HW_FPU=y >>>>>>>>>> CONFIG_XENO_HW_UNLOCKED_SWITCH=y >>>>>>>>>> ... >>>>>>>>>> # >>>>>>>>>> # At least one emulation must be selected >>>>>>>>>> # >>>>>>>>>> CONFIG_VFP=y >>>>>>>>>> CONFIG_VFPv3=y >>>>>>>>>> CONFIG_NEON=y >>>>>>>>>> CONFIG_VFP_3_2_BACKPORT=y >>>>>>>>>> ... >>>>>>>>>> ============================================ >>>>>>>>>> >>>>>>>>>> Is it possible to use ***hardware floating point*** with >>>>>>>>>> realtime >>>>>>>>>> user-space tasks ? >>>>>>>>> >>>>>>>>> Yes, it should be. Do you get the same issue when running both >>>>>>>>> the >>>>>>>>> switchtest and switchtest -s 1000 tests? Do you have the same >>>>>>>>> issue >>>>>>>>> with the I-pipe patch for Linux 3.8? >>>>>>>>> >>>>>>>>> >>>>>>>> / # ./switchtest -s 1000 >>>>>>>> == Testing FPU check routines... >>>>>>>> d0: 1 != 2 >>>>>>>> d1: 1 != 2 >>>>>>>> d2: 1 != 2 >>>>>>>> d3: 1 != 2 >>>>>>>> d4: 1 != 2 >>>>>>>> d5: 1 != 2 >>>>>>>> d6: 1 != 2 >>>>>>>> d7: 1 != 2 >>>>>>>> d8: 1 != 2 >>>>>>>> d9: 1 != 2 >>>>>>>> d10: 1 != 2 >>>>>>>> d11: 1 != 2 >>>>>>>> d12: 1 != 2 >>>>>>>> d13: 1 != 2 >>>>>>>> d14: 1 != 2 >>>>>>>> d15: 1 != 2 >>>>>>>> == FPU check routines: OK. >>>>>>>> >>>>>>>> / # ./switchtest >>>>>>>> == Testing FPU check routines... >>>>>>>> d0: 1 != 2 >>>>>>>> d1: 1 != 2 >>>>>>>> d2: 1 != 2 >>>>>>>> d3: 1 != 2 >>>>>>>> d4: 1 != 2 >>>>>>>> d5: 1 != 2 >>>>>>>> d6: 1 != 2 >>>>>>>> d7: 1 != 2 >>>>>>>> d8: 1 != 2 >>>>>>>> d9: 1 != 2 >>>>>>>> d10: 1 != 2 >>>>>>>> d11: 1 != 2 >>>>>>>> d12: 1 != 2 >>>>>>>> d13: 1 != 2 >>>>>>>> d14: 1 != 2 >>>>>>>> d15: 1 != 2 >>>>>>>> == FPU check routines: OK. >>>>>>>> >>>>>>>> As you can see the test seems OK. >>>>>>>> But If I understand correctly switchtest is not a real-time test. >>>>>>> >>>>>>> You do not understand correctly. You should run >>>>>>> switchtest & switchtest -s 1000 >>>>>>> >>>>>>> And let them run for some time. >>>>>>> >>>>>>>> I see the problem If I use my floating point test. >>>>>>>> I try to calculate sin(2x). >>>>>>>> Then I claculate 2*sin(x)*cos(x). >>>>>>>> They should be similar. But sometime they are very different ===> >>>>>>>> fpu >>>>>>>> error >>>>>>>> >>>>>>>> >>>>>>>> I have kerne 3.0.35. >>>>>>>> For me it is not so easy try 3.8. >>>>>>> >>>>>>> How is that? To test xenomai you do not need all the drivers, just >>>>>>> the >>>>>>> uart. >>>>>>> >>>>>>> >>>>>> I'm able to do it. >>>>>> But I'm paid for use this board. Try I cannot loose too time to test >>>>>> configurations that we will not use. >>>>>> I understand you, but you should try to understand me. >>>>>> Have you got some ideas ? >>>>> >>>>> I have given you my ideas. Of course, you are free to ignore them and >>>>> debug the issue on your own. >>>>> >>>>> >>>> I understand your hard words. >>>> I understand only because in my life I worked (in my free time) on a >>>> very complex project : colinux64. >>>> If you do not know, colinux is a porting of linux kernel on windows. >>>> Only who works on these complex parts of the system know the hard >>>> works >>>> there is to do and what it means find bug. The same complexity of >>>> xenomai. >>>> >>>> I have done my homework, but not in xenomai project world. >>>> Repeat, I understand your words ... but remember that not all the >>>> people >>>> are stupid and do not want to find bug. >>>> You do not know the skills of the persons on the other side, so my >>>> advice is to try to understand which kind of person you are >>>> contacting. >>>> It is not so easy ... but it could be important in your work. >>> >>> What are you talking about? You ask a question, I reply rapidly with >>> some ideas to test. You do not want to test these ideas, so the >>> conclusion is: debug the issue on your own. I do not know any other >>> answer than the one I gave you. >>> >>> >> Studying the problem it seems that xenomai works fine. >> The problem maybe is related to not re-entrance of sin and cos function. >> If I use simple float operation I do not see the problem. >> >> I have the same problem using two non realtime task, so I can say that >> the problem is not related to xenomai. > > In order to be sure that the bug is not introduced by Xenomai, you > should disable CONFIG_XENOMAI, CONFIG_IPIPE, and in fact, even try the > unpatched kernel. And again: you can use the switchtest tool to test > whether FPU is OK (with CONFIG_XENOMAI), and if switchtest fails after > some time, we have tools to make debugging much easier. > > Also note that the 3.0 kernel was released more than 3 years ago, so > it is entirely possible that mainline bugs have been fixed since then, > both on Linux side, and on I-pipe side, which is the reason I asked > you to test a more recent kernel. > I'm sorry ... all works correctly, also with hardware floating point. It was all my fault. Paolo