On Fri, Sep 15, 2017 at 12:29 PM, Andy Lutomirski <l...@amacapital.net> wrote: > > >> On Sep 15, 2017, at 11:47 AM, Linus Torvalds <torva...@linux-foundation.org> >> wrote: >> >>> On Fri, Sep 15, 2017 at 3:22 AM, Pavel Machek <pa...@ucw.cz> wrote: >>> >>> Let me pull latest... >>> >>> 711aab1dbb324d321e3d84368a435a78908c7bce >>> >>> (Strange. Not authored by Linus and old?) >> >> That's the author date, the committer date is new. Top of tree right >> now just happens to be a patch I applied, it's much more commonly a >> merge I've done. >> >>> But result is still similar, this time with more debug information. >>> [ 0.116813] x86: Booting SMP configuration: >>> [ 0.116893] .... node #0, CPUs: #1 >>> [ 0.004000] Initializing CPU#1 >>> [ 0.004000] ------------[ cut here ]------------ >>> [ 0.004000] WARNING: CPU: 1 PID: 0 at arch/x86/mm/tlb.c:257 >>> initialize_tlbstate_and_flush+0x2e/0xed >>> [ 0.004000] Hardware name: LENOVO 17097HU/17097HU, BIOS 7BETD8WW (2.19 ) >>> 03/31/2011 >>> [ 0.004000] task: f5ca2080 task.stack: f5cc4000 >>> [ 0.004000] EIP: initialize_tlbstate_and_flush+0x2e/0xed >>> [ 0.004000] EFLAGS: 00210087 CPU: 1 >>> [ 0.004000] EAX: 0504b000 EBX: c4f15540 ECX: c4f15710 EDX: 00000000 >>> [ 0.004000] ESI: 04ee7000 EDI: f5ca2080 EBP: f5cc5f54 ESP: f5cc5f44 >>> [ 0.004000] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 >>> [ 0.004000] CR0: 80050033 CR2: 00000000 CR3: 04ee7000 CR4: 000006b0 >>> [ 0.004000] Call Trace: >>> [ 0.004000] cpu_init+0xdc/0x2f0 >>> [ 0.004000] start_secondary+0x34/0x1c6 >>> [ 0.004000] startup_32_smp+0x164/0x166 >>> [ 0.004000] ? startup_32_smp+0x164/0x166 >>> [ 0.004000] Code: 56 53 83 ec 08 64 8b 1d c0 c0 03 c5 b9 10 57 f1 c4 e8 >>> de 65 9e 00 89 45 f0 89 55 f4 0f 20 de 8b 43 20 05 00 00 00 40 39 c6 74 11 >>> <0f> ff 50 56 68 74 9c d8 c4 e8 d1 cd 04 00 83 c4 0c a1 20 90 f8 >>> [ 0.004000] ---[ end trace 7439e29925a49b51 ]--- >>> [ 0.004000] # CR3: 0000000004ee7000, __pa(mm->pgd): 000000000504b000 >> >> Ok, clearly Andy didn't get the 32-bit SMP bringup path right. >> Presumable tested a 32-bit UP image, or in a single-cpu VM? >> >> Andy? > > The warning only triggers on 32-bit SMP. The issue seems to be that > boot_cpu_has(X86_FEATURE_PCID) is true despite setup_clear_cpu_cap. I'm > still trying to figure out why. I'll hopefully have a patch after lunch.
Nah, that was a false alarm although there's arguably a real bug here. But I found the issue causing the warning. x86's boot code is so inconsistent and weird that I'm a bit surprised that it works at all sometimes. > >> >> Linus
