----- On Jan 28, 2016, at 8:57 AM, Peter Zijlstra [email protected] wrote:
> On Thu, Jan 28, 2016 at 01:38:00PM +0000, Mathieu Desnoyers wrote: > >> Thoughts ? > > So ideally dumping the trace data would not depend on any of that, > because I can break it all :-) > > Not being able to access the trace data completely and utterly defeats > the purpose of having a tracer in the first place. One item I have on my todo list is to allow mapping the tracer buffers (lttng in my case) onto RAM that persists across reboots/kexec using dax and the pmem driver. Since the original system is clearly inactive after a reboot, we can read the buffers from memory without caring about synchronization. That would be one possible way of handling your snapshot-of-buggy-kernel-trace-buffers use-case. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
