a memory tracking tool
allocscope is a tool for tracking down where the most egregiously large allocations are occurring
in a C, C++ or Rust codebase. It is particilarly intendend to be useful for developers who want to
get a handle on excessive allocations and are working in a large codebase with multiple
contributors with allocations occuring in many modules or libraries.
It is composed of two commands:
allocscope-trace
attaches to another process as a debugger. By using breakpoints on memory
allocation functions such as malloc
it tracks allocations made by that process. During the
trace, the callstack of all allocations are recorded to an .atrace
file. Tracing programs
which spawn multiple threads and tracing calls through shared libraries are supported. You can
spawn a process to trace by specifying a full commandline to allocscope-trace
, or you can
attach to an existing running process.
allocscope-view
reads the .atrace
file produced by allocscope-trace
. It presents a summary
of all allocations made in a call tree format, which can be sorted by largest concurrent
allocation, total number of blocks, number of unfreed allocation blocks, or the sequence of
the allocation. The summary can be navigated interactively through a curses-based terminal user
interface, or a text report suitable for non-interactive use can be generated.
Installing prebuilt binaries
The easiest way to get started with allocscope is to install prebuilt binaries.
To install the latest version:
curl -s https://allocscope.com/install.sh | sudo sh
Currently only Linux on x86_64 processors is supported, but I’d like to support more operating systems
and processors in the future.
Getting started
While it will be likely be most useful to use allocscope on a program with symbols, which you
have compiled yourself, you can verify that it functions correctly by performing a trace on a
standard system command, such as ls
:
allocscope-trace ls -l