High memory use on Rust 1.51.0 with thin LTO and debuginfo

[jonasmalacofilho]

Rust 1.50.0 is able to link the example bellow using a few GB of memory, but 1.51.0/nightly needs at least 30 GB, at which point either I or the OOM killer has to abort it.

// src/main.rs

use actix_web::{web, App, HttpServer, Responder};
use std::net::TcpListener;

async fn greet() -> impl Responder {
 "Hello, World!"
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    let listener = TcpListener::bind("127.0.0.1:8080")?;

    HttpServer::new(|| App::new().route("/", web::get().to(greet)))
        .listen(listener)?
        .run()
        .await?;

    Ok(())
}

# Cargo.toml

[package]
name = "example"
version = "0.1.0"
authors = ["Jonas Malaco <[email protected]>"]
edition = "2018"

[dependencies]
actix-web = "3.3"
reqwest = "0.10"

[profile.release]
lto = "thin"
debug = true

I wasn't able to reduce it beyond this, at least for now. Removing the unused dependency to reqwest, changing the LTO setting to false or fat, disabling debuginfo, or using -Clinker-plugin-lto are, each, enough to bring back the memory consumption to manageable levels.

After being aborted by the OOM killer, this is the error message:

$ cargo build --release
   [ ... ]
   Compiling example v0.1.0 (/home/jonas/Code/issues/rust/1.51-explosive-lto)
error: could not compile `example`

Caused by:
  process didn't exit successfully: `rustc --crate-name example --edition=2018 src/main.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C opt-level=3 -C lto=thin -C debuginfo=2 -C metadata=576df4506149e7e2 -C extra-filename=-576df4506149e7e2 --out-dir <pwd>/target/release/deps -L dependency=<pwd>/target/release/deps --extern actix_web=<pwd>/target/release/deps/libactix_web-e15a9d0e8b71dcac.rlib --extern reqwest=<pwd>/target/release/deps/libreqwest-953a39d56f962952.rlib -L native=<pwd>/target/release/build/brotli-sys-7accbad0b10c603b/out` (signal: 9, SIGKILL: kill)

Meta

rustc --version --verbose (stable):

rustc 1.51.0 (2fd73fabe 2021-03-23)
binary: rustc
commit-hash: 2fd73fabe469357a12c2c974c140f67e7cdd76d0
commit-date: 2021-03-23
host: x86_64-unknown-linux-gnu
release: 1.51.0
LLVM version: 11.0.1

rustc --version --verbose (nightly):

rustc 1.53.0-nightly (07e0e2ec2 2021-03-24)
binary: rustc
commit-hash: 07e0e2ec268c140e607e1ac7f49f145612d0f597
commit-date: 2021-03-24
host: x86_64-unknown-linux-gnu
release: 1.53.0-nightly
LLVM version: 12.0.0

[apiraino]

Assigning priority as discussed as part of the Prioritization Working Group procedure and removing I-prioritize.

@rustbot label -I-prioritize +P-high

[jonasmalacofilho]

Bisected from nightly-2021-01-01 to nightly-2021-03-24:

searched nightlies: from nightly-2021-01-01 to nightly-2021-03-24
regressed nightly: nightly-2021-02-06
searched commits: from 4f4656d to 23adf9f
regressed commit: 5605b5d

bisected with cargo-bisect-rustc v0.6.0

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --start 2021-01-01 --end 2021-03-24 -- build --release 

---

That said, this is no longer reproduceable starting¹ with nightly-2021-04-02.

Bisected (non-error) from from nightly-2021-03-31 to nightly-2021-04-02:

searched nightlies: from nightly-2021-03-31 to nightly-2021-04-02
regressed nightly: nightly-2021-04-02
searched commits: from 4fdac23 to d474075
regressed commit: 803ddb8

bisected with cargo-bisect-rustc v0.6.0

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --start 2021-03-31 --end 2021-04-02 --regress=non-error -- build --release 

¹ I wasn't able to manually install nightly-2021-04-01 with rustup.

[pnkfelix]

Based on previous comment, namely:

That said, this is no longer reproduceable starting1 with nightly-2021-04-02.

I'm going to close this as fixed.