On Tue, May 28, 2019 at 09:22:14PM +0200, Jiri Kosina wrote: > On Tue, 28 May 2019, Jiri Kosina wrote: > > > [ some x86/PM folks added ] > > > > I isolated this to 'nosmt' being present in the "outer" (resuming) kernel, > > and am still not sure whether this is x86 issue or nvme/PCI/blk-mq issue. > > > > For the newcomers to this thread: on my thinkpad x270, 'nosmt' reliably > > breaks resume from hibernation; after the image is read out from disk and > > attempt is made to jump to the old kernel, machine reboots.
> > Thomas figured it out (and this should be really more widespread than just > my machine :) ). > > nosmt forces HT siblings to mwait, but that explodes after %cr3 change > during resume, as the mwait target address is all of a sudden not valid > anymore for neither of the hyperthreads. ARGH!!! But also, you wrote: > > I verified that it succesfully makes it to the point where restore_image() > > is called from swsusp_arch_resume() (and verified that only BSP is alive > > at that time), but the old kernel never comes back and triplefault-like > > reboot happens. which means that even without nosmt all 'other' CPUs are offline. And when I look at resume_target_kernel() I see it call hibernate_resume_nonboot_cpu_disable(). So how is the SMT offline different from that offline? afaict they all get into play_dead()->native_play_dead()->mwait_play_dead().
