From mboxrd@z Thu Jan 1 00:00:00 1970 References: <7c43aa40-9754-2529-8bc7-7df8c7124a96@siemens.com> <126b2b25b43ff4acbc3e5ffb902239e69fc67bfe.camel@siemens.com> <20210224112455.56da9faf@md1za8fc.ad001.siemens.net> <20210224123511.529fe032@md1za8fc.ad001.siemens.net> <87zgzs6ymo.fsf@xenomai.org> <12bfdd83-f44f-f152-9601-6f1038e4212a@siemens.com> <87tuq06xiq.fsf@xenomai.org> <878s767r3f.fsf@xenomai.org> <353a5ca7-7ccc-21df-983b-e6ca2cf5a73c@siemens.com> From: Philippe Gerum Subject: Re: [I-PIPE] ipipe-core-4.19.165-cip41-arm64-09 released In-reply-to: <353a5ca7-7ccc-21df-983b-e6ca2cf5a73c@siemens.com> Date: Fri, 05 Mar 2021 10:34:29 +0100 Message-ID: <87wnumx7tm.fsf@xenomai.org> MIME-Version: 1.0 Content-Type: text/plain List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Henning Schild , Henning Schild via Xenomai , "Bezdeka, Florian (T RDA IOT SES-DE)" , Greg Gallagher Jan Kiszka writes: > On 01.03.21 17:53, Philippe Gerum wrote: >> >> Jan Kiszka writes: >> >>> On 25.02.21 15:18, Philippe Gerum wrote: >>>> >>>> Jan Kiszka writes: >>>> >>>>> On 25.02.21 14:54, Philippe Gerum wrote: >>>>>> >>>>>> Jan Kiszka writes: >>>>>> >>>>>>> On 24.02.21 12:35, Henning Schild via Xenomai wrote: >>>>>>>> Am Wed, 24 Feb 2021 11:24:55 +0100 >>>>>>>> schrieb Henning Schild via Xenomai : >>>>>>>> >>>>>>>>> Am Wed, 10 Feb 2021 12:08:43 +0100 >>>>>>>>> schrieb Jan Kiszka via Xenomai : >>>>>>>>> >>>>>>>>>> On 10.02.21 11:07, Bezdeka, Florian (T RDA IOT SES-DE) wrote: >>>>>>>>>>> On Wed, 2021-02-10 at 09:15 +0100, Jan Kiszka via Xenomai wrote: >>>>>>>>>>> >>>>>>>>>>>> On 10.02.21 07:22, xenomai--- via Xenomai wrote: >>>>>>>>>>>>> Download URL: >>>>>>>>>>>>> https://xenomai.org/downloads/ipipe/v4.x/arm64/ipipe-core-4.19.165-cip41-arm64-09.patch >>>>>>>>>>>>> >>>>>>>>>>>>> Repository: https://git.xenomai.org/ipipe-arm64 >>>>>>>>>>>>> Release tag: ipipe-core-4.19.165-cip41-arm64-09 >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Hmm, now we have the 5.4-arm64 issue also on 4.19: >>>>>>>>>>>> https://gitlab.denx.de/Xenomai/xenomai-images/-/jobs/219984 >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> I don't know much about the things going on here, but found this >>>>>>>>>>> line in the log. Maybe a starting point... >>>>>>>>>>> >>>>>>>>>>> 2021-02-10T07:51:47 setsched.c:120, assertion failed: stats.msw == >>>>>>>>>>> msw >>>>>>>>>> >>>>>>>>>> Exactly, that is causing the overall failure. And it was first seen >>>>>>>>>> with the newly added 5.4 kernel. >>>>>>>>> >>>>>>>>> Seing the same on amd64 when testing on qemu, real HW is fine. >>>>>>>>> >>>>>>>>> Managed to bisect it down to 4.19.147-cip (good) 4.19.150-cip (bad) >>>>>>>>> >>>>>>>>> Which also means that ipipe-core-4.19.152-cip37-x86-15 is affected. >>>>>>>>> >>>>>>>>> https://gitlab.denx.de/Xenomai/xenomai-images/-/jobs/200646 >>>>>>>>> did not find it, so maybe our config differs >>>>>>> >>>>>>> Already compared yours against the one in xenomai-images? That would be >>>>>>> useful. >>>>>>> >>>>>>>> >>>>>>>> Digging further i found 0f0b6099c45ff3e06d2487816cf1ff30d21835f6 likely >>>>>>>> causing the problem. >>>>>>>> >>>>>>>> ipipe-core-4.19.152-cip37-x86-15 <- bad >>>>>>>> revert 2b294ac325c7ce3f36854b74d0d1d89dc1d1d8b8 >>>>>>>> revert 8579a0440381353e0a71dd6a4d4371be8457eac4 <- bad >>>>>>>> revert 0f0b6099c45ff3e06d2487816cf1ff30d <- good >>>>>>>> >>>>>>>> I think here Jan or Phillipe should take over. >>>>>>> >>>>>>> Thanks for bisecting, this is helpful! >>>>>>> >>>>>>> Philippe, any immediate idea why all that is failing now? >>>>>> >>>>>> Something may be going wrong with MAP_SHARED mappings wrt commit_vma() >>>>>> in Dovetail. I'm adding this to my debug queue. >>>>>> >>>>> >>>>> This is still I-pipe, not a dovetail-related issues. >>>> >>>> This I-pipe release mimics what Dovetail does wrt mm pinning. >>>> >>> >>> Any news on this from your side? >>> >> >> No time slot for working on this yet. High multiplexing rate ATM. >> > > I reproduced the issue on qemu-arm64 (xenomai-images exposes it > directly), and I'm testing a fix. > > Brief summary: > Removal of un-COW support was a mistake. We will continue to require it > because it not only affects the child (where the removal argumentation > was targeting), but it also prevents that shared pages - even if locked > - on a RT parent suddenly become read-only. > > Expect some patches later today. The best fix is not add that ugly code back, but rather make VMA commit code work with shared mappings. -- Philippe.