On Thu, Jun 18, 2020 at 08:01:38PM -0400, Steven Rostedt wrote: > On Thu, 18 Jun 2020 15:19:01 -0700 > "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote: > > > For future reference, the TPS() around strings is not optional. Without > > it, trace messages from crash dumps are garbled, if I remember correctly. > > When you pass in a string like this, only the pointer to the string is > saved in the ring buffer. User space tools have no idea what those > pointers are. The TPS() around strings maps those pointers to the > string and shows them in the /sys/kernel/tracing/printk_formats file, > such that perf and trace-cmd know how to make sense of those strings. Makes sense. Quite a valuable feature! thanks, - Joel
