* jerome zh ([email protected]) wrote: > Hi all, > > In normal steps, we have to call the lttctl -D trace1 to stop a trace > and this makes lttng to write the trace buffer to the trace files. > So I am wondering how the trace can be stoped if the a kernel panic happens > and the kernel crashes before calling the lttctl -D trace ?
You'll have to use a tool to extract the trace buffers from the crashed kernel memory image. Then you can append the last subbuffers at the end of the tracefiles containing information from the channels already recorded. Make sure you enable the "LTT_VMCORE" LTTng config option so you have consistent last subbuffers when the kernel crashes. You must use the "commit_seq" counter of the last subbuffers to know how much contiguous information has been written in the last subbuffer. I fear that the "crash" tool extentions will not be up to date with the latest LTTng data structures though. Thanks, Mathieu -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com _______________________________________________ ltt-dev mailing list [email protected] http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
