JFYI I have those patches tested on the largish box. Will come back to you as soon as I have some feedback. I will also try to review these patches sometimes next week. Thanks! On Thu 06-08-15 14:45:43, Hidehiro Kawai wrote: > When an HA cluster software or administrator detects non-response > of a host, they issue an NMI to the host to completely stop current > works and take a crash dump. If the kernel has already panicked > or is capturing a crash dump at that time, further NMI can cause > a crash dump failure. > > Also, crash_kexec() called from oops context and panic() can > cause race conditions. > > To solve these issue, this patch set does following things: > > - Don't panic on NMI if the kernel has already panicked > - Extend exclusion control currently done by panic_lock to crash_kexec > - Introduce "noextnmi" boot option which masks external NMI at the > boot time (supported only for x86) > > V3: > - Introduce nmi_panic() macro to reduce code duplication > - In the case of panic on NMI, don't return from NMI handlers > if another cpu already panicked > > V2: > - Use atomic_cmpxchg() instead of current spin_trylock() to exclude > concurrent accesses to panic() and crash_kexec() > - Don't introduce no-lock version of panic() and crash_kexec() > > --- > > Hidehiro Kawai (4): > panic/x86: Fix re-entrance problem due to panic on NMI > panic/x86: Allow cpus to save registers even if they are looping in NMI context > kexec: Fix race between panic() and crash_kexec() called directly > x86/apic: Introduce noextnmi boot option > > > Documentation/kernel-parameters.txt | 4 ++++ > arch/x86/kernel/apic/apic.c | 17 ++++++++++++++++- > arch/x86/kernel/nmi.c | 15 +++++++++++---- > arch/x86/kernel/reboot.c | 11 +++++++++++ > include/linux/kernel.h | 21 +++++++++++++++++++++ > kernel/kexec.c | 20 ++++++++++++++++++++ > kernel/panic.c | 23 ++++++++++++++++++++--- > kernel/watchdog.c | 5 +++-- > 8 files changed, 106 insertions(+), 10 deletions(-) > > > -- > Hidehiro Kawai > Hitachi, Ltd. Research & Development Group > > -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
