Prof

This is in a very early prototyping stage and is Linux only right now.

There are a lot of great tools that can profile Rust programs from the C / C++ ecosystem, this aims to wrap them in an easy-to-use CLI that will eventually be cross-platform, providing a human-readable output as well as json that can be piped to other tools such as UI's.

Quickstart

There are two versions:

Cargo

Runs on your Cargo targets

Install

cargo install cargo-prof

YAML output with bytes as text (human-readable)

cargo prof heap

allocated_total: 2KB 119B
frees: 11
allocations: 11
allocated_at_exit: 0B
blocks_at_exit: 0

JSON outputs with total bytes

cargo prof heap -j

{"allocated_total":2167,"frees":11,"allocations":11,"allocated_at_exit":0,"blocks_at_exit":0}

Standalone

Runs on any binary

Install

cargo install prof

Profile ripgrep if rg is on your path

prof leak --bin rg

Pass ripgrep some arguments to stress it and see if any memory leaks

prof leak --bin rg -- a -uuu

definitely_lost: 0B
indirectly_lost: 0B
possibly_lost: 528B
still_reachable: 369KB 218B
supressed: 0B
definitely_lost_blocks: 0
indrectly_lost_blocks: 0
possibly_lost_blocks: 9
still_reachable_blocks: 89
supressed_blocks: 0

Give grep a try as well and notice some data is leaked, even on a single file:

prof leak --bin grep -- a Cargo.toml 

definitely_lost: 272B
indirectly_lost: 352B
possibly_lost: 128B
still_reachable: 109KB 490B
supressed: 0B
definitely_lost_blocks: 272
indrectly_lost_blocks: 11
possibly_lost_blocks: 1
still_reachable_blocks: 15
supressed_blocks: 0

Other Commands

Other than leak and heap there is also cache for cache misses from cachegrind as percentages:

cargo prof cache

l1i: 0.36
l1d: 3.0
lli: 0.34
lld: 2.6
llt: 1.0

• l1i: percentage of level 1 cache instruction misses
• l1d: percentage of level 1 cache data misses
• lli: percentage of last level cache instruction misses (e.g. L3)
• lld: percentage of last level cache data misses (e.g. L3)
• llt: percentage of last level total cache misses

You can see a visual diagram of your cache levels with the command: lstopo

For more information on these numbers mean see official docs:

https://valgrind.org/docs/manual/cg-manual.html

Or for a good description on what a cache miss is, check out this great talk from Andrew Kelley the creator of Zig: https://vimeo.com/handmadeseattle/practical-data-oriented-design#t=280s