Linux Kernel trace events in pstore

About the Organization

Pstore is a subsystem in the Linux kernel that is used to store kernel logs which can retrieved after a machine warm-reboots. Currently, during ftrace tracing, ftrace events in the kernel are lost when a machine hard-locks up. There is a need for writing these events into the pstore so that after a lock up, the trace events that led to the crash can be retrieved from the Pstore after a warm reboot. This has to be done in a scalable way so that tracing a live system does not impact performance of the system – ftrace is extremely fast. Initial patches posted to write and retrieve events to/from pstore are not scalable due to locking and other issues. Introducing a scalable approach will open up more possibilities for crash analysis. Prototype work for reference: https://linaroconnectsandiego.sched.com/event/Sue7/event-tracing-and-pstore-with-a-pinch-of-dynamic-debug