Hi- (same) On 3/23/20 3:30 PM, Guilherme G. Piccoli wrote: > > V2: Implemented grammar suggestions from Randy, Andrew and > Matthew. Thanks in advance for the reviews! > Cheers, > > Guilherme > > > .../admin-guide/kernel-parameters.txt | 8 +++++++ > Documentation/admin-guide/sysctl/kernel.rst | 17 +++++++++++++++ > include/linux/kernel.h | 6 ++++++ > kernel/panic.c | 21 +++++++++++++++++++ > kernel/sysctl.c | 11 ++++++++++ > 5 files changed, 63 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 7a14caac6c94..7db622028c00 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -3333,6 +3333,14 @@ > This will also cause panics on machine check exceptions. > Useful together with panic=30 to trigger a reboot. > > + oops_all_cpu_backtrace= > + [KNL] Should kernel generate backtraces on all cpus CPUs > + when oops occurs - this should be a last measure resort > + in case a kdump cannot be collected, for example. > + Defaults to 0 and can be controlled by the sysctl > + kernel.oops_all_cpu_backtrace. > + Format: <integer> > + > page_alloc.shuffle= > [KNL] Boolean flag to control whether the page allocator > should randomize its free lists. The randomization may > diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst > index 8b4ff69d2348..8660001d3a3e 100644 > --- a/Documentation/admin-guide/sysctl/kernel.rst > +++ b/Documentation/admin-guide/sysctl/kernel.rst > @@ -57,6 +57,7 @@ show up in /proc/sys/kernel: > - msgmnb > - msgmni > - nmi_watchdog > +- oops_all_cpu_backtrace > - osrelease > - ostype > - overflowgid > @@ -572,6 +573,22 @@ numa_balancing_scan_size_mb is how many megabytes worth of pages are > scanned for a given scan. > > > +oops_all_cpu_backtrace: > +================ > + > +If this option is set, the kernel will send an NMI to all CPUs to dump > +their backtraces when an oops event occurs. It should be used as a last > +resort in case a panic cannot be triggered (to protect VMs running, for > +example) or kdump can't be collected. This file shows up if CONFIG_SMP > +is enabled. > + > +0: Won't show all CPUs backtraces when an oops is detected. > +This is the default behavior. > + > +1: Will non-maskably interrupt all CPUs and dump their backtraces when > +an oops event is detected. > + > + > osrelease, ostype & version: > ============================ > thanks. -- ~Randy
