Re: [PATCH] of: introduce event tracepoints for dynamic device_node lifecyle

From: Steven Rostedt
Date: Wed Apr 19 2017 - 22:34:13 EST


On Wed, 19 Apr 2017 16:27:10 -0700
Tyrel Datwyler <turtle.in.the.kernel@xxxxxxxxx> wrote:

> # echo stacktrace > /sys/kernel/debug/tracing/trace_options
> # cat trace | grep -A6 "/pci@800000020000018"

Just to let you know that there is now stacktrace event triggers, where
you don't need to stacktrace all events, you can pick and choose. And
even filter the stack trace on specific fields of the event.

# cd /sys/kernel/debug/tracing
# echo "stacktrace if common_pid == $$ && reason == 3" \
> events/tlb/tlb_flush/trigger

# cat trace
bash-1103 [003] ...1 1290.100133: tlb_flush: pages:-1 reason:local mm shootdown (3)
bash-1103 [003] ...2 1290.100140: <stack trace>
=> copy_process.part.39
=> _do_fork
=> SyS_clone
=> do_syscall_64
=> return_from_SYSCALL_64

-- Steve