On Wed, Dec 14, 2016 at 01:39:27PM +0200, Konstantin Belousov wrote: > In other words, it is almost certainly the hang and not a fault causing > hang. This means that the machine is not compliant with the IA32 > architecture, in particular, the region reported as normal memory by > E820 BIOS service does not behave as normal memory. > > Since regardless of the option setting, the memory map is same, and > bootstrap page table only depend on the memory map, we use the same page > table when hanging and when operating correctly. We do not fault or hang > when the option is turned off, which together with the improved early > fault handling in the patch, makes it almost certain that the problem is > in hardware configuration and not in our early setup. > > Of course, the most puzzling part is that memory test makes the hang > go away, while repeating memory test operation only on the msgbuf region > does not. msgbuf is special in that it is located at TOHM (top of high > memory). It spans 128KB from below it to the last byte of the last > physical segment. > > The only ideas I have right now is that there is either a bug in the > Caching Agent/Home agent/IMC configuration in BIOS, in which case there > is nothing OS can do to mitigate it. Or it might be that the memory > map reported by CMS is wrong (you said that you use legacy boot, right > ?). This is not too surprising if true, because non-EFI boot code path > definitely get less and less testing. > > For the later case (potential bug in CMS), could you switch to EFI boot > mode and see whether the issue magically healths itself ? You could boot > from USB stick in EFI mode without reinstalling for test. I can't boot from USB stick -- this is remote DC and IPMI allow only CDROM emulation. OK, I am boot in UEFI 12.0 snapshot ISO. Boot ok. Can I convert installed OS to UEFI mode? > Do you use latest BIOS for your motherboard ? This is new MB (X10DRi) w/ BIOS 2.0, new is 2.1 but update is not simple (need to prepare bootable dos ISO, mostly utilites don't work under FreeBSD).Received on Wed Dec 14 2016 - 11:13:40 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:09 UTC