On Tue, 28 Apr 2020 12:41:33 -0600 Jonathan Corbet <corbet@xxxxxxx> wrote: > On Thu, 23 Apr 2020 20:36:50 +0200 > Stephen Kitt <steve@xxxxxxx> wrote: > > > Based on the ftrace documentation, the tp_printk boot parameter > > documentation, and the implementation in kernel/trace/trace.c. > > > > Signed-off-by: Stephen Kitt <steve@xxxxxxx> > > This one could benefit from an ack from Steve (CC'd). Also one other Thanks! I verified that the documentation is correct. Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> -- Steve > little nit below: > > > Documentation/admin-guide/sysctl/kernel.rst | 50 +++++++++++++++++++++ > > 1 file changed, 50 insertions(+) > > > > diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst > > index 82bfd5892663..d4bbdaf96ebc 100644 > > --- a/Documentation/admin-guide/sysctl/kernel.rst > > +++ b/Documentation/admin-guide/sysctl/kernel.rst > > @@ -265,6 +265,27 @@ domain names are in general different. For a detailed discussion > > see the ``hostname(1)`` man page. > > > > > > +ftrace_dump_on_oops > > +=================== > > + > > +Determines whether ``ftrace_dump()`` should be called on an oops (or > > +kernel panic). This will output the contents of the ftrace buffers to > > +the console. This is very useful for capturing traces that lead to > > +crashes and outputing it to a serial console. > > + > > += =================================================== > > +0 Disabled (default). > > +1 Dump buffers of all CPUs. > > +2 Dump the buffer of the CPU that triggered the oops. > > += =================================================== > > + > > + > > +ftrace_enabled, stack_tracer_enabled > > +==================================== > > + > > +See :doc:`/trace/ftrace`. > > + > > + > > hardlockup_all_cpu_backtrace > > ============================ > > > > @@ -1191,6 +1212,35 @@ If a value outside of this range is written to ``threads-max`` an > > ``EINVAL`` error occurs. > > > > > > +traceoff_on_warning > > +=================== > > + > > +When set, disables tracing (see :doc:`/trace/ftrace`) when a > > +``WARN()`` is hit. > > + > > + > > +tracepoint_printk > > +================= > > + > > +When tracepoints are sent to printk() (enabled by the ``tp_printk`` > > +boot parameter), this entry provides runtime control:: > > + > > + echo 0 > /proc/sys/kernel/tracepoint_printk > > + > > +will stop tracepoints from being sent to printk(), and > > + > > +:: > > I would just make that ", and::" and avoid the separate line. > > > + > > + echo 1 > /proc/sys/kernel/tracepoint_printk > > + > > +will send them to printk() again. > > + > > +This only works if the kernel was booted with ``tp_printk`` enabled. > > + > > +See :doc:`/admin-guide/kernel-parameters` and > > +:doc:`/trace/boottime-trace`. > > + > > + > > unknown_nmi_panic > > ================= > > > > Thanks, > > jon
