The recorder library implements low-cost always-on tracing, with three usage models:
1. Flight recorder: Dump information on recent events in case of crash 2. Tracing: Individual traces can be enabled using environment variables 3. Real-time graphing / control, using the recorder_scope application This short series introduces a new "recorder" back-end which connects to the recorder. Traces using the recorder are intentionally "always on". An example is given of how the recorder can also be used separately from generated traces. This can be useful if you want to enable multiple related traces for a particular topic. This series requires a small makefile fix submitted earlier, included here for convenience. Christophe de Dinechin (3): Makefile: Compute libraries for libqemuutil.a and libvhost-user.a trace: Add support for recorder back-end trace: Example of "centralized" recorder tracing Makefile | 2 ++ configure | 5 +++ hmp-commands.hx | 19 ++++++++-- monitor/misc.c | 27 ++++++++++++++ scripts/tracetool/backend/recorder.py | 51 +++++++++++++++++++++++++++ trace/Makefile.objs | 2 ++ trace/control.c | 7 ++++ trace/recorder.c | 22 ++++++++++++ trace/recorder.h | 34 ++++++++++++++++++ util/module.c | 8 +++++ util/qemu-thread-common.h | 7 ++++ 11 files changed, 182 insertions(+), 2 deletions(-) create mode 100644 scripts/tracetool/backend/recorder.py create mode 100644 trace/recorder.c create mode 100644 trace/recorder.h -- 2.26.2
