linux/arch/x86/kernel
Jiri Olsa 7b0501b1e7 x86/smp: Fix __max_logical_packages value setup
Frank reported kernel panic when he disabled several cores in BIOS
via following option:

  Core Disable Bitmap(Hex)   [0]

with number 0xFFE, which leaves 16 CPUs in system (out of 48).

The kernel panic below goes along with following messages:

 smpboot: Max logical packages: 2^M
 smpboot: APIC(0) Converting physical 0 to logical package 0^M
 smpboot: APIC(20) Converting physical 1 to logical package 1^M
 smpboot: APIC(40) Package 2 exceeds logical package map^M
 smpboot: CPU 8 APICId 40 disabled^M
 smpboot: APIC(60) Package 3 exceeds logical package map^M
 smpboot: CPU 12 APICId 60 disabled^M
 ...
 general protection fault: 0000 [#1] SMP^M
 Modules linked in:^M
 CPU: 15 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc5+ #1^M
 Hardware name: SGI UV300/UV300, BIOS SGI UV 300 series BIOS 05/25/2016^M
 task: ffff8801673e0000 ti: ffff8801673ac000 task.ti: ffff8801673ac000^M
 RIP: 0010:[<ffffffff81014d54>]  [<ffffffff81014d54>] uncore_change_context+0xd4/0x180^M
 ...
  [<ffffffff810158ac>] uncore_event_init_cpu+0x6c/0x70^M
  [<ffffffff81d8c91c>] intel_uncore_init+0x1c2/0x2dd^M
  [<ffffffff81d8c75a>] ? uncore_cpu_setup+0x17/0x17^M
  [<ffffffff81002190>] do_one_initcall+0x50/0x190^M
  [<ffffffff810ab193>] ? parse_args+0x293/0x480^M
  [<ffffffff81d87365>] kernel_init_freeable+0x1a5/0x249^M
  [<ffffffff81d86a35>] ? set_debug_rodata+0x12/0x12^M
  [<ffffffff816dc19e>] kernel_init+0xe/0x110^M
  [<ffffffff816e93bf>] ret_from_fork+0x1f/0x40^M
  [<ffffffff816dc190>] ? rest_init+0x80/0x80^M

The reason for the panic is wrong value of __max_logical_packages,
which lets logical_package_map uninitialized and the uncore code
relying on this map being properly initialized (maybe we should
add some safety checks there as well).

The __max_logical_packages is computed as:

  DIV_ROUND_UP(total_cpus, ncpus);
  - ncpus being number of cores

With above BIOS setup we get total_cpus == 16 which set
__max_logical_packages to 2 (ncpus is 12).

Once topology_update_package_map processes CPU with logical
pkg over 2 we display above messages and fail to initialize
the physical_to_logical_pkg map, which makes the uncore code
crash.

The fix is to remove logical_package_map bitmap completely
and keep and update the logical_packages number instead.

After we enumerate all the present CPUs, we check if the
enumerated logical packages count is within its computed
maximum from BIOS data.

If it's not the case, we set this maximum to the new enumerated
value and freeze any new addition of logical packages.

The freeze is because lot of init code like uncore/rapl/cqm
depends on having maximum logical package value set to allocate
their data, so we can't change it later on.

Prarit Bhargava tested the patch and confirms that it solves
the problem:

  From dmidecode:
          Core Count: 24
          Core Enabled: 24
          Thread Count: 48

Orig kernel boot log:

 [    0.464981] smpboot: Max logical packages: 19
 [    0.469861] smpboot: APIC(0) Converting physical 0 to logical package 0
 [    0.477261] smpboot: APIC(40) Converting physical 1 to logical package 1
 [    0.484760] smpboot: APIC(80) Converting physical 2 to logical package 2
 [    0.492258] smpboot: APIC(c0) Converting physical 3 to logical package 3

1.  nr_cpus=8, should stop enumerating in package 0:

 [    0.533664] smpboot: APIC(0) Converting physical 0 to logical package 0
 [    0.539596] smpboot: Max logical packages: 19

2.  max_cpus=8, should still enumerate all packages:

 [    0.526494] smpboot: APIC(0) Converting physical 0 to logical package 0
 [    0.532428] smpboot: APIC(40) Converting physical 1 to logical package 1
 [    0.538456] smpboot: APIC(80) Converting physical 2 to logical package 2
 [    0.544486] smpboot: APIC(c0) Converting physical 3 to logical package 3
 [    0.550524] smpboot: Max logical packages: 19

3.  nr_cpus=49 ( 2 socket + 1 core on 3rd socket), should stop enumerating in
    package 2:

 [    0.521378] smpboot: APIC(0) Converting physical 0 to logical package 0
 [    0.527314] smpboot: APIC(40) Converting physical 1 to logical package 1
 [    0.533345] smpboot: APIC(80) Converting physical 2 to logical package 2
 [    0.539368] smpboot: Max logical packages: 19

4.  maxcpus=49, should still enumerate all packages:

 [    0.525591] smpboot: APIC(0) Converting physical 0 to logical package 0
 [    0.531525] smpboot: APIC(40) Converting physical 1 to logical package 1
 [    0.537547] smpboot: APIC(80) Converting physical 2 to logical package 2
 [    0.543579] smpboot: APIC(c0) Converting physical 3 to logical package 3
 [    0.549624] smpboot: Max logical packages: 19

5.  kdump (nr_cpus=1) works as well.

Reported-by: Frank Ramsay <framsay@redhat.com>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160815101700.GA30090@krava
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-18 10:14:48 +02:00
..
acpi Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
apic Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-12 14:31:10 -07:00
cpu x86/microcode/AMD: Fix initrd loading with CONFIG_RANDOMIZE_MEMORY=y 2016-08-18 10:06:49 +02:00
fpu x86/mm/pkeys: Fix compact mode by removing protection keys' XSAVE buffer manipulation 2016-08-10 16:12:26 +02:00
kprobes kprobes/x86: Clear TF bit in fault on single-stepping 2016-06-14 12:00:54 +02:00
.gitignore
alternative.c x86/asm: Stop depending on ptrace.h in alternative.h 2016-04-29 11:56:40 +02:00
amd_gart_64.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
amd_nb.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
apb_timer.c x86/apb_timer: Convert to hotplug state machine 2016-07-15 10:40:22 +02:00
aperture_64.c param: convert some "on"/"off" users to strtobool 2016-03-17 15:09:34 -07:00
apm_32.c x86/apm32: Remove paravirt_enabled() use 2016-04-22 10:29:03 +02:00
asm-offsets_32.c x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup 2016-03-10 09:48:14 +01:00
asm-offsets_64.c x86/syscalls: Add syscall entry qualifiers 2016-01-29 09:46:38 +01:00
asm-offsets.c x86/uaccess: Move thread_info::addr_limit to thread_struct 2016-07-15 10:26:30 +02:00
audit_64.c
bootflag.c
check.c Linux 4.2-rc8 2015-08-25 09:59:19 +02:00
cpuid.c new helpers: no_seek_end_llseek{,_size}() 2015-12-23 10:41:31 -05:00
crash_dump_32.c
crash_dump_64.c
crash.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
devicetree.c x86/cpufeature: Replace cpu_has_apic with boot_cpu_has() usage 2016-04-13 11:37:41 +02:00
doublefault.c
dumpstack_32.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
dumpstack_64.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
dumpstack.c Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-25 18:18:04 -07:00
e820.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-15 09:32:27 -07:00
early_printk.c x86: Fix misspellings in comments 2016-02-24 08:44:58 +01:00
early-quirks.c Linux 4.7 2016-07-26 17:26:29 +10:00
ebda.c x86/boot: Simplify EBDA-vs-BIOS reservation logic 2016-07-22 11:46:01 +02:00
espfix_64.c x86: get rid of superfluous __GFP_REPEAT 2016-06-24 17:23:52 -07:00
ftrace.c Nothing major this round. Mostly small clean ups and fixes. 2016-03-24 10:52:25 -07:00
head32.c x86/boot: Run reserve_bios_regions() after we initialize the memory map 2016-08-11 11:14:59 +02:00
head64.c x86/boot: Run reserve_bios_regions() after we initialize the memory map 2016-08-11 11:14:59 +02:00
head_32.S Merge branch 'x86/urgent' into x86/asm, to refresh the tree 2016-04-29 11:55:04 +02:00
head_64.S x86/mm: Enable KASLR for physical mapping memory regions 2016-07-08 17:35:15 +02:00
hpet.c x86/hpet: Fix /dev/rtc breakage caused by RTC cleanup 2016-08-10 14:37:06 +02:00
hw_breakpoint.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
i386_ksyms_32.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
i8237.c
i8253.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
i8259.c x86/irq: Probe for PIC presence before allocating descs for legacy IRQs 2015-11-07 10:37:37 +01:00
io_delay.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
ioport.c x86/iopl: Fix iopl capability check on Xen PV 2016-03-17 09:49:27 +01:00
irq_32.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
irq_64.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
irq_work.c treewide: Remove old email address 2015-11-23 09:44:58 +01:00
irq.c x86/irq: Do not substract irq_tlb_count from irq_call_count 2016-08-11 11:14:59 +02:00
irqinit.c
jump_label.c x86/asm: Stop depending on ptrace.h in alternative.h 2016-04-29 11:56:40 +02:00
kdebugfs.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
kexec-bzimage64.c KEYS: Generalise system_verify_data() to provide access to internal content 2016-04-06 16:14:24 +01:00
kgdb.c x86/asm: Stop depending on ptrace.h in alternative.h 2016-04-29 11:56:40 +02:00
ksysfs.c
kvm.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
kvmclock.c x86: Fix misspellings in comments 2016-02-24 08:44:58 +01:00
ldt.c x86/mm: Factor out LDT init from context init 2016-02-18 19:46:31 +01:00
machine_kexec_32.c
machine_kexec_64.c kexec: provide arch_kexec_protect(unprotect)_crashkres() 2016-05-23 17:04:14 -07:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching 2016-05-17 17:11:27 -07:00
mcount_64.S ftrace/x86: Set ftrace_stub to weak to prevent gcc from using short jumps to it 2016-05-20 13:28:40 -04:00
mmconf-fam10h_64.c
module.c x86/asm: Stop depending on ptrace.h in alternative.h 2016-04-29 11:56:40 +02:00
mpparse.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
msr.c x86/cpufeature: Carve out X86_FEATURE_* 2016-01-30 11:22:17 +01:00
nmi_selftest.c
nmi.c x86: include linux/ratelimit.h in nmi.c 2016-06-06 17:10:15 +02:00
paravirt_patch_32.c x86/paravirt: Remove the unused irq_enable_sysexit pv op 2015-11-23 10:48:16 +01:00
paravirt_patch_64.c x86/entry, x86/paravirt: Remove the unused usergs_sysret32 PV op 2015-11-23 10:48:16 +01:00
paravirt-spinlocks.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
paravirt.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
pci-calgary_64.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
pci-dma.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
pci-iommu_table.c x86: Fix non-static inlines 2016-04-16 13:21:40 +02:00
pci-nommu.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
pci-swiotlb.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
pcspeaker.c
perf_regs.c
platform-quirks.c x86/boot: Reorganize and clean up the BIOS area reservation code 2016-07-21 10:11:57 +02:00
pmem.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
probe_roms.c
process_32.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
process_64.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
process.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
ptrace.c x86/ptrace: Stop setting TS_COMPAT in ptrace code 2016-07-27 11:09:43 +02:00
pvclock.c pvclock: introduce seqcount-like API 2016-08-04 13:52:21 +02:00
quirks.c timers/x86/hpet: Type adjustments 2015-10-21 11:17:32 +02:00
reboot_fixups_32.c
reboot.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
relocate_kernel_32.S
relocate_kernel_64.S
resource.c
rtc.c char/genrtc: x86: remove remnants of asm/rtc.h 2016-06-04 00:20:07 +02:00
setup_percpu.c x86/acpi: store ACPI ids from MADT for future usage 2016-07-25 13:30:53 +01:00
setup.c x86/boot: Defer setup_real_mode() to early_initcall time 2016-08-11 11:15:00 +02:00
signal_compat.c x86/signals: Add build-time checks to the siginfo compat code 2016-06-14 12:19:24 +02:00
signal.c Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-06 09:04:35 -04:00
smp.c x86/smp: Remove single IPI wrapper 2015-11-05 13:07:54 +01:00
smpboot.c x86/smp: Fix __max_logical_packages value setup 2016-08-18 10:14:48 +02:00
stacktrace.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
step.c
sys_x86_64.c
sysfb_efi.c Merge branch 'linus' into efi/core, to pick up fixes 2016-05-07 07:00:07 +02:00
sysfb_simplefb.c
sysfb.c
tboot.c x86/tboot: Convert to hotplug state machine 2016-07-15 10:40:30 +02:00
tce_64.c x86/cpufeature: Remove cpu_has_clflush 2016-03-31 13:35:09 +02:00
test_nx.c x86/mm: Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option 2016-02-22 08:51:38 +01:00
test_rodata.c x86: Don't use module.h just for AUTHOR / LICENSE tags 2016-07-14 13:04:20 +02:00
time.c
tls.c x86/tls: Synchronize segment registers in set_thread_area() 2016-04-29 11:56:42 +02:00
tls.h
topology.c
trace_clock.c
tracepoint.c
traps.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
tsc_msr.c x86/tsc_msr: Remove irqoff around MSR-based TSC enumeration 2016-07-11 21:30:12 +02:00
tsc_sync.c
tsc.c Merge branch 'linus' into timers/urgent, to pick up fixes 2016-08-10 14:36:23 +02:00
uprobes.c uprobes/x86: Fix RIP-relative handling of EVEX-encoded instructions 2016-08-12 08:29:24 +02:00
verify_cpu.S x86/cpufeature: Carve out X86_FEATURE_* 2016-01-30 11:22:17 +01:00
vm86_32.c x86, bitops: remove use of "sbb" to return CF 2016-06-08 12:41:20 -07:00
vmlinux.lds.S x86/boot: Move compressed kernel to the end of the decompression buffer 2016-04-29 11:03:29 +02:00
vsmp_64.c
x86_init.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00
x8664_ksyms_64.c Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-01 14:23:42 -04:00