From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [I-PIPE] ipipe-core-4.19.165-cip41-arm64-09 released 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> <87wnumx7tm.fsf@xenomai.org> From: Jan Kiszka Message-ID: <39c37516-fef1-f337-7dca-7eef5069adaf@siemens.com> Date: Fri, 5 Mar 2021 11:54:28 +0100 MIME-Version: 1.0 In-Reply-To: <87wnumx7tm.fsf@xenomai.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum Cc: Henning Schild , Henning Schild via Xenomai , "Bezdeka, Florian (T RDA IOT SES-DE)" , Greg Gallagher On 05.03.21 10:34, Philippe Gerum wrote: > > 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. > What exactly do you mean? We must avoid that shared pages (with the child) become read-only on the parent. How to do that other than un-COWing? Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux