From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <5366943E.30008@xenomai.org> Date: Sun, 04 May 2014 21:25:50 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <1396407588.27578.5.camel@localhost.localdomain> <1396999856.2660.7.camel@localhost.localdomain> <53449244.8040502@xenomai.org> <1397003664.2660.14.camel@localhost.localdomain> <1397017658.2660.16.camel@localhost.localdomain> <534534FD.5090805@xenomai.org> <1397113300.2720.5.camel@localhost.localdomain> <5346895B.6080401@xenomai.org> <1397159850.2881.3.camel@localhost.localdomain> <53471389.6000000@xenomai.org> <1397168263.6356.11.camel@localhost.localdomain> <534719F5.2020605@xenomai.org> <1397169248.6356.15.camel@localhost.localdomain> <53471FDB.50008@xenomai.org> <1397170339.6356.17.camel@localhost.localdomain> <1397541812.6541.3.camel@localhost.localdomain> <534D19FA.3040506@xenomai.org> <1397599195.2652.0.camel@localhost.localdomain> <5356F4FE.3050406@xenomai.org> <1398217532.2723.18.camel@localhost.localdomain> <5359827E.7040900@xenomai.org> <1398735970.3038.1.camel@localhost.localdomain> In-Reply-To: <1398735970.3038.1.camel@localhost.localdomain> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] OMAP L138 List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Howard Cc: xenomai@xenomai.org On 04/29/2014 03:46 AM, Peter Howard wrote: > On Thu, 2014-04-24 at 23:30 +0200, Gilles Chanteperdrix wrote: >> On 04/23/2014 03:45 AM, Peter Howard wrote: >>> On Wed, 2014-04-23 at 01:02 +0200, Gilles Chanteperdrix wrote: >>>> On 04/15/2014 11:59 PM, Peter Howard wrote: >>>>> On Tue, 2014-04-15 at 13:37 +0200, Gilles Chanteperdrix wrote: >>>>>> On 04/15/2014 08:03 AM, Peter Howard wrote: >>>>>>> On Fri, 2014-04-11 at 08:52 +1000, Peter Howard wrote: >>>>>>>> On Fri, 2014-04-11 at 00:48 +0200, Gilles Chanteperdrix wrote: >>>>>>>>> On 04/11/2014 12:34 AM, Peter Howard wrote: >>>>>>>>>> On Fri, 2014-04-11 at 00:23 +0200, Gilles Chanteperdrix wrote: >>>>>>>>>> (Stripping back conversation on this one - apologies if that's bad >>>>>>>>>> etiquette for this list) >>>>>>>>>> >>>>>>>>>>> Attachment is better. Also please post the changes you made for omapL138 >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig >>>>>>>>>> index a075b3e..3d8bc59 100644 >>>>>>>>>> --- a/arch/arm/mach-davinci/Kconfig >>>>>>>>>> +++ b/arch/arm/mach-davinci/Kconfig >>>>>>>>>> @@ -41,6 +41,8 @@ config ARCH_DAVINCI_DA850 >>>>>>>>>> select ARCH_DAVINCI_DA8XX >>>>>>>>>> select ARCH_HAS_CPUFREQ >>>>>>>>>> select CP_INTC >>>>>>>>>> + select IPIPE_ARM_KUSER_TSC if IPIPE >>>>>>>>>> + select ARM_FCSE if IPIPE >>>>>>>>> >>>>>>>>> You may want to leave the choice of enabling or disabling FCSE to the user. >>>>>>>>> >>>>>>>> >>>>>>>> Understood; at the moment the variance on max latency is really bad if >>>>>>>> you don't enable FCSE. When I sort out the crashing issues I'll re-test >>>>>>>> with it off. >>>>>>> >>>>>>> Well, FCSE turned out to be my problem. >>>>>>> >>>>>>> More specifically, FCSE and ARM_FCSE_BEST_EFFORT. Either a) disabling >>>>>>> ARM_FCSE altogether, or b) selecting ARM_FCSE with ARM_FCSE_GUARENTEED >>>>>>> gets rid of the crashes/panics with ipipe latency tracing enabled. >>>>>>> >>>>>>> So now things seem reasonably stable, I'll go through the full set of >>>>>>> tests. Though I still can't do 'xeno-test -l "dohell -l /opt/ltp"' as >>>>>>> ltp takes out the system without any ipipe/xenomai bits. >>>>>>> >>>>>> Ok, FCSE best effort is currently being validated on 3.14, so it may >>>>>> well be broken. After all, the raw/* branches are work in progress. >>>>>> >>>>> >>>>> Note: selecting ARM_FCSE_BEST_EFFORT produces the same result on the >>>>> master branch too . . . >>>>> >>>> Hi Peter, >>>> >>>> I am unable to reproduce these issues with 3.14, FCSE seems to be doing >>>> just fine, I can boot and run the LTP testsuite and get almost the same >>>> results as a non patched kernel. I have tried with and without >>>> preemptible cache flushes, and with and without Xenomai. My rootfs is >>>> based on busybox and minimal, maybe that is the reason why it works >>>> fine, could you put a tarball with your rootfs somewhere? >>> >>> A bit of testing shows (at least) one case is directly related to the >>> rootfs. This is the Texas Instruments rootfs that is supplied for the >>> DA850 board. During normal startup, it wants to start the GUI for the >>> LCD which would go past the 32MB process limit with FCSE enabled. With >>> FCSE_GUARENTEED selected this is noted but doesn't cause a crash. With >>> FCSE_BEST_EFFORT selected this is noted and then the system crashes >>> within a few seconds. I'm not sure if this counts as a bug in >>> BEST_EFFORT or whether all bets are off if you try to start a process >>> that's too large. >>> >>> At this point I'm not sure if anything else is specific to that rootfs >>> but I'll still make it available to you to have a look. >> >> No luck with your rootfs: matrix_GUI craches indeed, but it also crashes >> without CONFIG_FCSE, so it would seem the crash is unrelated to the >> FCSE. Obviously it does not crash with FCSE_GUARANTEED, because it is >> stopped as soon as it wants to go over 32 MB. And that crash does not >> cause the cascade of crashes you mentioned, ending with init crashing. >> The processor on which I am running the tests does not have a >> framebuffer maybe that is the reason I get a crash, and do not go as far >> as in your case. >> >> Could you post the kernel configuration you use? >> > > Take 3. Ignore the previous two. They will probably trigger it, but > this one I actually tested to confirm it does cause the crash. This configuration with only omapl138 replaced with at91sam9263 seems to run correctly, except for the segfault in the matrix_guiE application, which I also have on an unpatched kernel. Note that this configuration sets the cache to writethrough mode which, at least on at91sam9263 results in a much slower kernel than writeback mode. So, I would say any remaining issue is specific to omapl138. -- Gilles.