Hi- On 3/10/20 9:37 AM, Guilherme G. Piccoli wrote: > > Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx> > --- > > As a P.S. note, my choice to put the backtrace dump in the end of > oops_enter() was from previous experience (in which I used this > approach in a kprobes to collect more data on oops), but I'd > gladly accept suggestion in case there's a better place to dump > this. Thanks in advance for the reviews! > Cheers, > > Guilherme > > > .../admin-guide/kernel-parameters.txt | 8 +++++++ > Documentation/admin-guide/sysctl/kernel.rst | 15 +++++++++++++ > include/linux/kernel.h | 6 ++++++ > kernel/panic.c | 21 +++++++++++++++++++ > kernel/sysctl.c | 11 ++++++++++ > 5 files changed, 61 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 4c6595b5f6c8..888b1fab3f6e 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 generates backtraces on all cpus generate backtraces on all 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 218c717c1354..460112c3f656 100644 > --- a/Documentation/admin-guide/sysctl/kernel.rst > +++ b/Documentation/admin-guide/sysctl/kernel.rst > @@ -573,6 +574,20 @@ numa_balancing_scan_size_mb is how many megabytes worth of pages are > scanned for a given scan. > > > +oops_all_cpu_backtrace: > +================ > + > +Determines if kernel should NMI all CPUs to dump their backtraces when I would much prefer that to be written without using NMI as a verb. > +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 NMI all CPUs and dump their backtraces when an oops is detected. Same here. > + > + > osrelease, ostype & version: > ============================ > Thanks. -- ~Randy
