linux/arch
Anton Blanchard c54b2bf1b5 powerpc: Add ppc64 hard lockup detector support
The hard lockup detector uses a PMU event as a periodic NMI to
detect if we are stuck (where stuck means no timer interrupts have
occurred).

Ben's rework of the ppc64 soft disable code has made ppc64 PMU
exceptions a partial NMI. They can get disabled if an external
interrupt comes in, but otherwise PMU interrupts will fire in
interrupt disabled regions.

We disable the hard lockup detector by default for a few reasons:

- It breaks userspace event based branches on POWER8.
- It is likely to produce false positives on KVM guests.
- Since PMCs can only count to 2^31, counting cycles means we might
  take multiple PMU exceptions per second per hardware thread even
  if our hard lockup timeout is 10 seconds.

It can be enabled via a boot option, or via procfs.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-04-11 20:49:27 +10:00
..
alpha
arc
arm The clk fixes for 4.0-rc4 comprise three themes. First are the usual 2015-03-15 15:07:08 -07:00
arm64 arm64 fixes: 2015-03-14 09:32:00 -07:00
avr32
blackfin
c6x arch/c6x/include/asm/pgtable.h: define dummy pgprot_writecombine for !MMU 2015-03-12 18:46:08 -07:00
cris
frv
hexagon
ia64
m32r
m68k
metag
microblaze microblaze: Fix syscall error recovery for invalid syscall IDs 2015-03-04 15:12:27 +01:00
mips
mn10300
nios2 nios2: update pt_regs 2015-03-12 13:35:06 +08:00
openrisc
parisc
powerpc powerpc: Add ppc64 hard lockup detector support 2015-04-11 20:49:27 +10:00
s390 Merge git://git.kernel.org/pub/scm/virt/kvm/kvm 2015-03-09 18:59:50 -07:00
score
sh
sparc
tile
um
unicore32
x86 xen: bug fixes for 4.0-rc3 2015-03-13 13:34:38 -07:00
xtensa
.gitignore
Kconfig oprofile: Disable oprofile NMI timer on ppc64 2015-04-11 20:49:27 +10:00