[Qemu-devel] [PATCH v2 0/7] Tracing backends

[Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>]

After the RFC discussion, updated patches which I propose for review and merge:

The following patches against qemu.git allow static trace events to be declared
in QEMU.  Trace events use a lightweight syntax and are independent of the
backend tracing system (e.g. LTTng UST).

Supported backends are:
 * my trivial tracer ("simple")
 * LTTng Userspace Tracer ("ust")
 * no tracer ("nop", the default)

The ./configure option to choose a backend is --trace-backend=.

Main point of this patchset: adding new trace events is easy and we can switch
between backends without modifying the code.

These patches are also available at:
http://repo.or.cz/w/qemu/stefanha.git/shortlog/refs/heads/tracing

v2:
[PATCH 1/7] trace: Add trace-events file for declaring trace events
 * Use "$source_path/tracetool" in ./configure
 * Include qemu-common.h in trace.h so common types are available

[PATCH 2/7] trace: Support disabled events in trace-events
 * New in v2: makes it easy to build only a subset of trace events

[PATCH 3/7] trace: Add simple built-in tracing backend
 * Make simpletrace.py parse trace-events instead of generating Python

[PATCH 4/7] trace: Add LTTng Userspace Tracer backend

[PATCH 5/7] trace: Trace qemu_malloc() and qemu_vmalloc()
 * Record pointer result from allocation functions

[PATCH 6/7] trace: Trace virtio-blk, multiwrite, and paio_submit

[PATCH 7/7] trace: Trace virtqueue operations
 * New in v2: observe virtqueue buffer add/remove and notifies