# Feedback request: Performance improvements from reducing debug info

**URL:** <https://internals.rust-lang.org/t/feedback-request-performance-improvements-from-reducing-debug-info/21825>\
**Category:** Uncategorized\
**Created:** [November 5, 2024, 4:20pm UTC](https://internals.rust-lang.org/t/feedback-request-performance-improvements-from-reducing-debug-info/21825 "2024-11-05T16:20:29Z")\
**Posts on this page:** 1\
**Showing post:** 11

<div class="post-metadata">

**Author:** ![davidlattimore](https://sea2.discourse-cdn.com/flex002/user_avatar/internals.rust-lang.org/davidlattimore/32/5141_2.png) [@davidlattimore](https://internals.rust-lang.org/u/davidlattimore)\
**Post date:** [November 16, 2024, 4:02am UTC](https://internals.rust-lang.org/t/feedback-request-performance-improvements-from-reducing-debug-info/21825/11 "2024-11-16T04:02:20Z")

</div>

Ubuntu-based with Wild as the linker

Smallish build (10MiB binary):

```rust
default cold: 22.49s
line-tables cold: 20.78s
debug=0 cold: 19.66s

default warm: 0.24s
line-tables warm: 0.20s
debug=0 warm: 0.18s

```

Larger build (several binaries around 450MiB each):

```rust
default cold: 4m 51s
line-tables cold: 3m 46s
debug=0 cold: 3m 16s

default warm: 4.48s
line-tables warm: 2.28s
debug=0 warm: 1.63s

```

I recently ran an informal survey about [whether people regularly use a debugger](https://mas.to/@davidlattimore/113484821980790635). Of the 89 responses, 18% say they sometimes or always use a debugger while 82% say they rarely or never use a debugger. This seems consistent with what I've observed from talking to rustaceans in person.

I'm definitely supportive of any change to reduce the debug info for a default build.

I think that line number information in backtraces is less important now that it used to be and the reason is `#[track_caller]`. Generally the line that I care about when I get a backtrace is the line that called unwrap, expect, panic etc and these days that line is reported whether or not you have line debug info. So personally, I set `debug=0`, but I can understand that's likely a step too far for the default - just changing to `line-tables` by default would be great.

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_[View the full topic](https://internals.rust-lang.org/t/feedback-request-performance-improvements-from-reducing-debug-info/21825)._