On 22/03/2020 18:16, Bhupesh Sharma wrote: > Hello Guilherme, > > On Fri, Mar 20, 2020 at 9:10 PM Guilherme G. Piccoli > <gpiccoli@xxxxxxxxxxxxx> wrote: > > Thanks for writing again. I was caught up in trying several other > suggestions/code-snippets to further debug this. > I tried several combinations - turning iommu off, turning off swiotlb > in the kexec kernel and testing various combinations with > retain_initrd added to the kexec kernel's bootargs. > > But nothing seems to fix the nested repetitive kexec reboot attempts > on the aws t3 machines I have. It just becomes better on few instances > (i.e. the kexec reboots would survive around 10 nested repetitive > attempts), while on the other(s) the failure can be seen quite > frequently (approx ~3 kexec reboot attempts). Hi Bhupesh, thanks for the tests! Indeed, this problem is difficult to prevent with those parameters, and it's quite interesting to see how it may vary among instances. > [...] > This is a really good debug and resulting patch. > I ran almost ~60 kexec repetitive attempts last night and also > repeated the same today morning and > the issue seems to get fixed for me with upstream kernel 5.6.0-rc6+ > with this patch. > > I am leaving a test running with RHEL kernel + this patch overnight > and will have more updates to share by tomorrow morning. Thanks a lot =) I couldn't fail to give due credit to my friend Gavin Shan for the great suggestion that resulted in the patch! Let me know your results with the patch Bhupesh, and your Tested-by on it is much appreciated. > >> Bhupesh, I've noticed that suddenly the Red Hat bugzilla got private - > > Oops. I will check. > >> is it okay to add me in CC list so I can see it? > > Sure. I tried doing it, but seems Bugzilla is not happy as it keeps > complaining that you are not registered on BZ, > I will try to find out internally how to get around the issue. > Great! If you need me to sign-up in Bugzilla, I can do it. Just let me know the steps and I'd be glad in doing that. >> Thanks for all the collaboration, I hope the issue was figured and solved! > > Sure. Thanks a lot for your inputs and trying the suggestions I posted > on the Bugzilla ticket. > I will soon share an update with RHEL/Fedora kernel kexec tests with > this patch applied and also reply with a Tested-by for the upstream > patch in the relevant thread. > > Thanks, > Bhupesh > Thank you, I appreciate the tests and collaboration =) Cheers, Guilherme _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
