[+cc Martin, Rafael, Len, linux-acpi] On Tue, Nov 13, 2018 at 11:20:04AM +0100, Borislav Petkov wrote: > On Tue, Nov 13, 2018 at 08:17:12AM +0100, Ingo Molnar wrote: > > > > * Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > > > > PCI changes: > > > > > > - Pay attention to device-specific _PXM node values (Jonathan Cameron) > > > > There's a new boot regression, my AMD ThreadRipper system (MSI X399 SLI > > PLUS (MS-7B09)) hangs during early bootup, and I have bisected it down to > > this commit: > > > > bad7dcd94f39: ACPI/PCI: Pay attention to device-specific _PXM node values > > > > Reverting it solves the hang. > > > > Unfortunately there's no console output when it hangs, even with > > earlyprintk. It just hangs after the "loading initrd" line. > > > > Config is an Ubuntu-ish config with PROVE_LOCKING=y and a few other debug > > options. > > > > All my other testsystems boot fine with similar configs, so it's probably > > something specific to this system. Martin reported the same thing [1] (unfortunately the archive didn't capture Martin's original emails, I think because they were multi-part messages with attachments). Looks like Martin might have a similar system: DMI: To Be Filled By O.E.M. To Be Filled By O.E.M./X399 Taichi, BIOS P3.30 08/14/2018 smpboot: CPU0: AMD Ryzen Threadripper 2950X 16-Core Processor (family: 0x17, model: 0x8, stepping: 0x2) Given how painful this is to debug, I queued up a revert on my for-linus branch until we figure out what sanity checks are needed to make the original patch safe. I would expect proximity information to be basically just a hint for optimization, not a functional requirement, so it would be really interesting to figure out why this causes such a catastrophic failure. Maybe there's a way to improve that path as well so it would be more robust or at least more debuggable. Bjorn [1] https://lore.kernel.org/linux-pci/20180912152140.3676-2-Jonathan.Cameron@xxxxxxxxxx
