33c81a3a9c
This brings over some of the techniques from the old memprof design. Sysprof and memprof shared a lot of code, so it is pretty natural to bring back the same callgraph view based on memory allocations. This reuses the StackStash just like it did in memprof. While it would be nice to reuse some existing tools out there, the fit of memprof with sysprof is so naturally aligned, it's not really a big deal to bring back the LD_PRELOAD. The value really comes from seeing all this stuff together instead of multiple apps. There are plenty of things we can implement on top of this that we are not doing yet such as temporary allocations, cross-thread frees, graphing the heap, and graphing differences between the heap at to points in time. I'd like all of these things, given enough time to make them useful. This is still a bit slow though due to the global lock we take to access the writer. To improve the speed here we need to get rid of that lock and head towards a design that allows a thread to request a new writer from Sysprof and save it in TLS (to be destroyed when the thread exits).
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.
Questions, patches and bug reports should be sent to the sysprof mailing list sysprof-list@gnome.org.
The 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 25:
sudo dnf install gcc gcc-c++ ninja-build gtk3-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.