This starts the perf streams from prepare instead of from record so that we can do the linux instrument work in prepare. The samples are dropped until our start-time is set. Doing it this way removes sysprof-cli and sysprofd greatly from the overhead in the callgraph which is useful so that the user gets to see what they really care about. It has the added benefit that we're less likely to see the pkla processes showing up from authorizing our D-Bus connection for creating per streams.
Sysprof is a sampling profiler that uses a kernel module to generate stacktraces which are then interpreted by the userspace program "sysprof".
See the Sysprof homepage for more information.
Merge requests and bug reports should be sent to sysprof's repository on GNOME's GitLab instance. For general discussion and questions, you can create a new topic in GNOME's Discourse.
The former mailing list is archived in https://mail.gnome.org/archives/sysprof-list/.
Debugging symbols
The programs and libraries you want to profile should be compiled
with -fno-omit-frame-pointer and have debugging symbols available,
or you won't get much usable information.
Building Sysprof
You need some packages installed. The package names may vary depending on your distribution, the following command works on Fedora 36:
sudo dnf install gcc gcc-c++ ninja-build gtk4-devel libadwaita-devel
Then do the following:
meson --prefix=/usr build
cd build
ninja
sudo ninja install
WARNING: ninja install will mostly install under the configured install
prefix but installs systemd service configuration directly in the system
default location /usr/lib/systemd so it won't work without root privileges,
even if the install prefix is a user-owned directory.