So we have just seen an issue that looks oddly familiar to this in kernel 4.4.5
On Mon, Sep 21, 2015 at 10:03 PM, Greg Young <gregoryyou...@gmail.com> wrote: > I am surprised to see no one else post on this. > > I would think a massive regression that prevents mono from running > multi-threaded code on a multi-cpu system (including in the future on > any v4 kernel) might be an issue that people would be concerned > about?! > > > > On Thu, Sep 17, 2015 at 4:03 PM, Greg Young <gregoryyou...@gmail.com> wrote: >> So to follow up on this. >> >> The fix that was put in for this has since been reverted as mentioned >> in the bug above. >> >> https://github.com/torvalds/linux/commit/73459e2a1ada09a68c02cc5b73f3116fc8194b3d >> >> So all 4 kernels will have this issue. I'm not really sure what needs >> to be done on the mono side here to avoid this issue but it would seem >> to affect any multi-threaded code running on multiple cpu linux >> systems (which I would imagine would be a vast majority of mono >> installations). >> >> Greg >> >> On Thu, Sep 17, 2015 at 1:05 PM, Greg Young <gregoryyou...@gmail.com> wrote: >>> I was just actually writing that this seems to be discussed here: >>> https://bugzilla.xamarin.com/show_bug.cgi?id=29692 :) Thanks for the >>> additional information. >>> >>> >>> >>> On Thu, Sep 17, 2015 at 1:01 PM, Taloth Saldono <talothsald...@gmail.com> >>> wrote: >>>> This Ubuntu bug discusses the issue for 3.13. >>>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1450584 >>>> >>>> Please note that later kernel 4.0 versions exhibit similar issues, search >>>> this mailinglist for specifics on that new regression. I gave up on >>>> investigating further due to other obligations and the complexity of the >>>> subject matter. >>>> >>>> Op 17 sep. 2015 11:49 schreef "Greg Young" <gregoryyou...@gmail.com>: >>>>> >>>>> 3.13.0-63-generic does not have the issue as well. >>>>> >>>>> I guess our mitigation will just be to know about the issue and >>>>> suggest downgrade/upgrade. This may however be useful for others in >>>>> the future. Mono 3.12.1 on 3.13.0-46-generic #77-Ubuntu SMP appears to >>>>> not be stable. We will also test mono4 now. >>>>> >>>>> Greg >>>>> >>>>> On Thu, Sep 17, 2015 at 11:38 AM, Greg Young <gregoryyou...@gmail.com> >>>>> wrote: >>>>> > We are running into some interesting regressions with mono. We are >>>>> > seeing many failures such as: >>>>> > >>>>> > Mono v3.12.1 (we have considered moving up to 4.1 or 4.2 but the last >>>>> > time we tested it didn't seem safe to move). >>>>> > >>>>> > Native stacktrace: >>>>> > >>>>> > /home/ubuntu/EventStore-OSS-Ubuntu-v3.2.1/eventstored() [0x609a4f] >>>>> > /home/ubuntu/EventStore-OSS-Ubuntu-v3.2.1/eventstored() [0x5bdecf] >>>>> > /home/ubuntu/EventStore-OSS-Ubuntu-v3.2.1/eventstored() [0x453b19] >>>>> > /lib/x86_64-linux-gnu/libpthread.so.0(+0x10340) [0x7fd9709b7340] >>>>> > /home/ubuntu/EventStore-OSS-Ubuntu-v3.2.1/eventstored() [0x4e6145] >>>>> > [0x40e21ceb] >>>>> > >>>>> > >>>>> > [03041,21,13:43:11.379] Global Unhandled Exception occurred. >>>>> > Object reference not set to an instance of an object >>>>> > [ERROR] FATAL UNHANDLED EXCEPTION: System.NullReferenceException: >>>>> > Object reference not set to an instance of an object >>>>> > at EventStore.Core.Bus.QueuedHandlerAutoReset.ReadFromQueue >>>>> > (System.Object o) [0x00000] in <filename unknown>:0 >>>>> > at System.Threading.Thread.StartInternal () [0x00000] in <filename >>>>> > unknown>:0 >>>>> > >>>>> > note that this isn't a real nre >>>>> > >>>>> > We do not see these regressions in Linux ip-172-31-37-60 >>>>> > 3.13.0-46-generic #77-Ubuntu SMP >>>>> > >>>>> > We do see them in Linux ip-172-31-40-115 3.13.0-48-generic #80-Ubuntu >>>>> > SMP >>>>> > >>>>> > Anyone have any ideas how to debug this further? These are not >>>>> > deterministic issues. >>>>> > >>>>> > Cheers, >>>>> > >>>>> > Greg >>>>> > >>>>> > -- >>>>> > Studying for the Turing test >>>>> >>>>> >>>>> >>>>> -- >>>>> Studying for the Turing test >>>>> _______________________________________________ >>>>> Mono-devel-list mailing list >>>>> Mono-devel-list@lists.ximian.com >>>>> http://lists.ximian.com/mailman/listinfo/mono-devel-list >>> >>> >>> >>> -- >>> Studying for the Turing test >> >> >> >> -- >> Studying for the Turing test > > > > -- > Studying for the Turing test -- Studying for the Turing test _______________________________________________ Mono-devel-list mailing list Mono-devel-list@lists.ximian.com http://lists.ximian.com/mailman/listinfo/mono-devel-list