[ Resending without corrupted email headers ]
I'm happy to announce that after over a year, we finally are able to
release trace-cmd version 3.0!
The two biggest changes:
1) Updated trace.dat to version 7 (not compatible with older versions of
trace-cmd). But now supports compression.
2) Better synchronization between host and guest kernel tracing.
Features and user visible updates since 2.9:
- Relies on upstream repos for libtraceevent and libtracefs:
* Removed libtraceevent code (Upstream minimum version 1.5)
* Removed libtracefs code (Upstream minimum version 1.3)
- KernelShark is no longer installed in the trace-cmd repo.
- Some perf support
- trace-cmd dump updates:
* Display the clock used in the file
- New trace-cmd clock: tsc2nsec to use the tsc clock in the ring buffer but
to display it as nanoseconds. Requires architecture support, but trace-cmd
list -C will show if it supported or not.
- New option --raw-ts for trace-cmd report to show raw timestamps without any
modifications.
- New timestamp synchronization between host and guests.
* P2P : timing back and forth of host and guest
* KVM : queries the kernel for the multiplier, offset and shift for exact
synchronization of host and guest timestamps.
- tracecmd_warning() API for writing error messages in libtracecmd library.
- Better bash tab completion.
- Plugins now go into /usr/[local/]lib/trace-cmd instead of traceevent
directory.
- New option --full for trace-cmd list to show "print fmt" of event formats
specified by -e <event> -F
- trace-cmd list now shows ftrace events as well as events that can be
enabled.
- Supports non qemu VM host/guest tracing.
- New option --align-ts for trace-cmd report that will make the timestamps of
all events a delta from the first event. (0.000003 instead of 16292.633984)
- New option -V for trace-cmd report to change verbosity.
- New option --verbose for a bunch of commands to trace-cmd.
- New option --poll for trace-cmd record to poll which makes trace-cmd check
the buffers with O_NONBLOCK instead of relying on IPIs to wake it up. This
reduces latency on recording tasks that trace-cmd is not running on.
- trace.dat output has been updated to Version 7 (incompatible with older
trace-cmd, but trace-cmd convert can convert back to version 6, with
possible lost of features).
* The file is broken up into sections (defined as options) just like an ELF
file.
* Allows for sections to be compressed.
. Supports zlib compression
. Supports ZSTD compression
* Will allow for new types of data to be added
. Target for perf data to be included (still in development)
- New command: trace-cmd convert, to convert between trace-cmd 7 and 6 files.
|