On Fri, Dec 29, 2017 at 1:02 PM, Toralf Förster <toralf.foerster@xxxxxx> wrote: > On 12/29/2017 09:12 PM, Linus Torvalds wrote: >> instead, and see if that makes a difference, that would narrow down >> the possible root cause of this problem. > > not at this ThinkPad T440s (didn't test at the server with an i7-3930). > > Boot stops just at: > > tsc: Refined TSC clocksource calibration: 2494.225 MHz > clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x23f3ea95b09, max_idle_ns: 440795287034 ns Uhhuh. So for Alexander Troy, just getting rid of the -march=core2 fixed the boot. But not for you. Strange. It really looked like the exact same thing. > This is a "Intel(R) Core(TM) i5-4300U CPU @ 1.90GHz" with gcc-6.4 Yeah, other reporters of this have used gcc-6.4.0 too. But there's been some muddying of the waters there too - changing compilers have fixed it for some cases, but there's at least one report that a kernel build with gcc-7.2.0 still had the issue (and another that said it didn't). But the MCORE2 was consistent for several people - including you. Until this point. Strange. The only other thing (apart from the compiler flag) that MCORE2 results in is to enable CONFIG_X86_INTEL_USERCOPY CONFIG_X86_USE_PPRO_CHECKSUM CONFIG_X86_P6_NOP and the two first of those shouldn't even matter on x86-64, and I don't see that last one making any difference either. So because it looks so impossible that the "-march=core2" didn't make a difference for you, I'll ask you to please double-check that you actually booted into the right kernel. Sorry for doubting you, but your report just broke the _one_ consistent thing we've seen about this bug. Linus