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uftrace v0.14
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@namhyung namhyung released this 20 Jun 06:09
· 195 commits to master since this release
v0.14
04d73dc

Release note

This release comes with new cool features and bug fixes.

Python tracing support

The first thing is Python language support! Now uftrace can trace python functions and methods like C/C++ functions. Internally, it uses python's sys.setprofile() and pass the entry/exit info to the libmcount.

For example, it can trace the following python script (it needs to be a standalone executable - it should have #! line and executable permission).

$ cat abc.py 
#! /usr/bin/python3
def a(): b()
def b(): c()
def c(): print("Hello")
if __name__ == '__main__':
    a()

$ chmod +x abc.py

Then uftrace can trace the functions like below:

$ uftrace abc.py 
Hello
# DURATION     TID     FUNCTION
            [235209] | __main__.<module>() {
            [235209] |   a() {
            [235209] |     b() {
            [235209] |       c() {
  10.810 us [235209] |         builtins.print();
  14.926 us [235209] |       } /* c */
  16.628 us [235209] |     } /* b */
  18.867 us [235209] |   } /* a */
  22.000 us [235209] | } /* __main__.<module> */

Not all features work well with python scripts, but filters by name (-F and -N), depth (-D), time (-t), location (-L) would work. However you can use full features for analysis after recording the data.

Runtime control with agent

The next is the improved agent control. The agent listens to a client connection in background when started with -g option. Then users can connect to it with uftrace live using -p <PID> option. The should be a process ID of the target, not the uftrace itself.

Say we want to trace my program with a filter at first. Please don't forget to start an agent.

$ uftrace record -g -F ^mycode -- myprog

Later we don't want to use the function filter anymore, and decided to use a time filter instead. Let's change the option for the uftrace record like below:

$ uftrace -p $(pidof myprog) -F ^mycode@clear -t 100us

Note that the above command would not produce any data and just pass the new options to the existing uftrace record session (for myprog).

Android (AOSP) build support

One more big thing is Android build support. While it's not officially supported, you can build uftrace as an external tool. This needed various improvements in terms of portability like abstracting shmem access and better handling of the tmp directory and dynamic linker behaviors.

It has been tested with Android 9+ on AArch64 and x86_64. You probably want to use dynamic tracing due to issues with the Android runtime. Please see INSTALL.md for the details.

Other important changes

The size filter at replay now works as same as record, since the symbol file format was changed to save the symbol size as well.

Symbol demangling on Rust programs was improved to handle trait names in a more compact way. The new demangling scheme (v0) is not supported yet.

There are also more fixes and improvements. Thank you all for making uftrace more useful, efficient and portable!

Full change list

New Contributors

Full Changelog: v0.13.1...v0.14

Contributors

namhyung, yugr, and 9 other contributors
Assets 2
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