linux/arch
Nicholas Piggin 2104180a53 powerpc/64s: implement arch-specific hardlockup watchdog
Implement an arch-speicfic watchdog rather than use the perf-based
hardlockup detector.

The new watchdog takes the soft-NMI directly, rather than going through
perf.  Perf interrupts are to be made maskable in future, so that would
prevent the perf detector from working in those regions.

Additionally, implement a SMP based detector where all CPUs watch one
another by pinging a shared cpumask.  This is because powerpc Book3S
does not have a true periodic local NMI, but some platforms do implement
a true NMI IPI.

If a CPU is stuck with interrupts hard disabled, the soft-NMI watchdog
does not work, but the SMP watchdog will.  Even on platforms without a
true NMI IPI to get a good trace from the stuck CPU, other CPUs will
notice the lockup sufficiently to report it and panic.

[npiggin@gmail.com: honor watchdog disable at boot/hotplug]
  Link: http://lkml.kernel.org/r/20170621001346.5bb337c9@roar.ozlabs.ibm.com
[npiggin@gmail.com: fix false positive warning at CPU unplug]
  Link: http://lkml.kernel.org/r/20170630080740.20766-1-npiggin@gmail.com
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170616065715.18390-6-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Tested-by: Babu Moger <babu.moger@oracle.com>	[sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:02 -07:00
..
alpha Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
arc Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 16:14:51 -07:00
arm arm: move ELF_ET_DYN_BASE to 4MB 2017-07-10 16:32:36 -07:00
arm64 arm64: move ELF_ET_DYN_BASE to 4GB / 4MB 2017-07-10 16:32:36 -07:00
blackfin kernel/watchdog: introduce arch_touch_nmi_watchdog() 2017-07-12 16:26:02 -07:00
c6x This is the first pull request for the new dma-mapping subsystem 2017-07-06 19:20:54 -07:00
cris Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
frv frv: cmpxchg: implement cmpxchg64() 2017-07-10 16:32:34 -07:00
h8300 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 16:14:51 -07:00
hexagon Merge branch 'akpm' (patches from Andrew) 2017-07-06 22:27:08 -07:00
ia64 kexec: move vmcoreinfo out of the kernel's .bss section 2017-07-12 16:25:59 -07:00
m32r Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2017-07-11 09:52:56 -07:00
metag Merge branch 'akpm' (patches from Andrew) 2017-07-06 22:27:08 -07:00
microblaze Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
mips lib/extable.c: use bsearch() library function in search_extable() 2017-07-10 16:32:35 -07:00
mn10300 kernel/watchdog: introduce arch_touch_nmi_watchdog() 2017-07-12 16:26:02 -07:00
nios2 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 16:14:51 -07:00
openrisc OpenRISC fixes for 4.13 2017-07-07 13:58:49 -07:00
parisc Merge branch 'akpm' (patches from Andrew) 2017-07-06 22:27:08 -07:00
powerpc powerpc/64s: implement arch-specific hardlockup watchdog 2017-07-12 16:26:02 -07:00
s390 kexec: move vmcoreinfo out of the kernel's .bss section 2017-07-12 16:25:59 -07:00
score Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
sh lib/extable.c: use bsearch() library function in search_extable() 2017-07-10 16:32:35 -07:00
sparc kernel/watchdog: introduce arch_touch_nmi_watchdog() 2017-07-12 16:26:02 -07:00
tile Kbuild thin archives updates for v4.13 2017-07-07 15:11:12 -07:00
um Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
unicore32
x86 kernel/watchdog: split up config options 2017-07-12 16:26:02 -07:00
xtensa Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
.gitignore
Kconfig kernel/watchdog: split up config options 2017-07-12 16:26:02 -07:00