binutils-strings-rust

What is that?

This project is a rewrite a Binutils strings utility in Rust (and without libbfd dependency).

It is just a personal interest to accomplish the following:

• Compare Rust vs C performance for the same algorithm.
• Explore the impact of different optimization changes.

Useful stuff

1. To print shared library dependencies: ldd target/release/strings.
2. Verbose run stats (CPU, context switches, memory usage, etc.): $(which time) --verbose target/release/strings target/debug/strings (don't confuse with bash built-in time).
3. To profile app run with stack traces: perf record -g target/release/strings target/debug/strings > /dev/null (and perf report to display the report).
4. To profile app run with stack traces (dwarf): perf record --call-graph dwarf target/release/strings target/debug/strings > /dev/null (and perf report to display the report).

NB: target/debug/strings is used as input, because this is a big binary (several MBs), which is enough to collect rich statistics.

Only all+ASCII performance comparison brings a meaningful result, because the difference is pretty much isolated to the language.

data section+ASCII performance comparison run has no meaning, because Rust version is using different backend to parse object file and also it is quite fast, so there is impact of app arguments definition load and parsing.

Unicode performance comparison run has a little trust, because C version crashes on a big file (target/debug/strings), so smaller file is used.

Performance comparison

strings version 2.38

ASCII chars search, complete file scan (file stream mode)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
target/release/strings target/debug/strings	864.2 ± 57.0	797.0	986.9	1.04 ± 0.08
strings target/debug/strings	831.4 ± 26.2	804.1	888.2	1.00

Rust variant memory usage and context switches

Maximum resident set size (kbytes): 2448
Voluntary context switches: 2924
Involuntary context switches: 6

C variant memory usage and context switches

Maximum resident set size (kbytes): 2572
Voluntary context switches: 5347
Involuntary context switches: 4

ASCII chars search, only data section(s) scan (in-memory byte array mode)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
target/release/strings -d target/debug/strings	161.5 ± 4.0	154.4	168.5	3.42 ± 0.21
strings -d target/debug/strings	47.3 ± 2.6	42.6	55.0	1.00

Rust variant memory usage and context switches

Maximum resident set size (kbytes): 23592
Voluntary context switches: 599
Involuntary context switches: 1

C variant memory usage and context switches

Maximum resident set size (kbytes): 4832
Voluntary context switches: 113
Involuntary context switches: 0

Unicode chars search, complete file scan (file stream mode)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
target/release/strings -u escape target/release/strings	260.3 ± 18.0	233.0	302.5	1.40 ± 0.12
strings -Ue target/release/strings	185.3 ± 9.8	175.8	208.7	1.00

Rust variant memory usage and context switches

Maximum resident set size (kbytes): 2460
Voluntary context switches: 830
Involuntary context switches: 1

C variant memory usage and context switches

Maximum resident set size (kbytes): 7784
Voluntary context switches: 1196
Involuntary context switches: 0