linux/arch
Paul Mackerras f74f2e2e26 KVM: PPC: Book3S HV: Don't dynamically split core when already split
In static micro-threading modes, the dynamic micro-threading code
is supposed to be disabled, because subcores can't make independent
decisions about what micro-threading mode to put the core in - there is
only one micro-threading mode for the whole core.  The code that
implements dynamic micro-threading checks for this, except that the
check was missed in one case.  This means that it is possible for a
subcore in static 2-way micro-threading mode to try to put the core
into 4-way micro-threading mode, which usually leads to stuck CPUs,
spinlock lockups, and other stalls in the host.

The problem was in the can_split_piggybacked_subcores() function, which
should always return false if the system is in a static micro-threading
mode.  This fixes the problem by making can_split_piggybacked_subcores()
use subcore_config_ok() for its checks, as subcore_config_ok() includes
the necessary check for the static micro-threading modes.

Credit to Gautham Shenoy for working out that the reason for the hangs
and stalls we were seeing was that we were trying to do dynamic 4-way
micro-threading while we were in static 2-way mode.

Fixes: b4deba5c41
Cc: vger@stable.kernel.org # v4.3
Signed-off-by: Paul Mackerras <paulus@samba.org>
2015-11-06 16:02:59 +11:00
..
alpha PCI updates for v4.3: 2015-09-25 11:16:53 -07:00
arc genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
arm KVM/ARM Changes for v4.4-rc1 2015-11-04 16:24:17 +01:00
arm64 KVM/ARM Changes for v4.4-rc1 2015-11-04 16:24:17 +01:00
avr32 genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
blackfin genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
c6x genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
cris CRISv10: delete unused lib/dmacopy.c 2015-09-05 00:56:51 +02:00
frv PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code" 2015-09-15 13:18:04 -05:00
h8300 dma-mapping: consolidate dma_set_mask 2015-09-10 13:29:01 -07:00
hexagon Merge branch 'akpm' (patches from Andrew) 2015-09-10 18:19:42 -07:00
ia64 PCI updates for v4.3: 2015-09-25 11:16:53 -07:00
m32r lib/decompressors: use real out buf size for gunzip with kernel 2015-09-10 13:29:01 -07:00
m68k genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
metag genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
microblaze PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code" 2015-09-15 13:18:04 -05:00
mips KVM/ARM Changes for v4.4-rc1 2015-11-04 16:24:17 +01:00
mn10300 PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code" 2015-09-15 13:18:04 -05:00
nios2 nios2: add Max10 defconfig 2015-09-08 18:16:02 +08:00
openrisc dma-mapping: consolidate dma_set_mask 2015-09-10 13:29:01 -07:00
parisc parisc: Use platform_device_register_simple("rtc-generic") 2015-09-08 17:53:48 +02:00
powerpc KVM: PPC: Book3S HV: Don't dynamically split core when already split 2015-11-06 16:02:59 +11:00
s390 KVM/ARM Changes for v4.4-rc1 2015-11-04 16:24:17 +01:00
score
sh genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
sparc genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
tile genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
um
unicore32 genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
x86 KVM: VMX: Fix commit which broke PML 2015-11-05 11:34:11 +01:00
xtensa PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code" 2015-09-15 13:18:04 -05:00
.gitignore
Kconfig kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00