heaptrack

# Profile a program (generates heaptrack.<prog>.<pid>.zst)
heaptrack ./myapp arg1 arg2
 
# Attach to running process
heaptrack --pid 12345
 
# Analyse the trace file
heaptrack_print heaptrack.myapp.12345.zst
 
# GUI analysis (if heaptrack-gui installed)
heaptrack_gui heaptrack.myapp.12345.zst

# Build with debug symbols (essential for readable backtraces)
cmake -S . -B build -DCMAKE_BUILD_TYPE=RelWithDebInfo
cmake --build build
 
# Then profile
heaptrack ./build/myapp

heaptrack_print heaptrack.myapp.*.zst 2>/dev/null

total runtime: 2.34s
calls to allocation functions: 145,234 (62,064/s)
temporary allocations: 89,123 (38,087/s)
peak heap memory consumption: 45.23MB
peak RSS (including heap): 78.45MB
total memory leaked: 2.34MB

# Top allocation hotspots (by peak memory)
hotspot 1: 12.34MB peak
  myapp::cache::Cache::insert(...)
    at src/cache.cpp:142
  ...

# Top leaked allocations
leak 1: 2.34MB leaked in 1,234 allocations
  myapp::connection::Connection::new(...)
    at src/connection.cpp:67

# Show top N hotspots
heaptrack_print -p 10 heaptrack.myapp.*.zst  # top 10 hotspots
 
# Show flamegraph data
heaptrack_print -f heaptrack.myapp.*.zst > alloc.folded
flamegraph.pl alloc.folded > alloc.svg
 
# Show only leaked allocations
heaptrack_print -l heaptrack.myapp.*.zst
 
# Show allocations above threshold
heaptrack_print --min-cost 1048576 heaptrack.myapp.*.zst  # >1MB only
 
# Short summary
heaptrack_print -s heaptrack.myapp.*.zst

# Record baseline
heaptrack ./myapp --config baseline.conf
mv heaptrack.myapp.*.zst before.zst
 
# Make changes, record again
heaptrack ./myapp --config new.conf
mv heaptrack.myapp.*.zst after.zst
 
# Compare (shows diff of hotspots)
heaptrack_print before.zst | head -20 > before.txt
heaptrack_print after.zst  | head -20 > after.txt
diff before.txt after.txt

// Rust: use system allocator so heaptrack can intercept
use std::alloc::System;
#[global_allocator]
static A: System = System;

# Profile Rust binary
cargo build --release
heaptrack ./target/release/myapp
 
# Note: debug symbols improve backtraces
cargo build --profile release-with-debug
heaptrack ./target/release-with-debug/myapp